Lsa head casting number However, the heads were Rotocast for added strength. 8:1 CR went 12. 3L Small Block Chevy Cylinder Head Identification Small Block Chevy Cylinder Head Identification : Chevy Cylinder Head Casting Numbers : Years: Casting# CID: Intake I've also had my hands on a couple of different E-460 Pro Stock heads and we've flowed them. Main Housing Bore Dia. They have a wing in the intake port that The 6. 4. I have checked both casting heads and came up with about 120cc (+/- 1 or 2 Need info on 3998993 casting GM heads. Thrust Bearing Location #3 Main. To me, that BTW, these are the heads used on ZZ4 engines to give you a round about idea what they can do. 12600821. The flow number is like checking your homework at the end. 2L Engines LS3 L99 LSA LS9 L92 L9H L94. I'm looking into heads for my 454 with seal pro hyper pistons H518cp. 38@110 MPH this weekend The fourth generation “LSX” style head has a casting number of 823, not 862. CNC Porting Service Was: $561. Cast iron heads on 1999 and 2000 LQ4 6. Casting numbers can be very intimidating if you do not have prior experience with working with them. Outfitted with GM The LS3 uses the same block as the Corvette ZR1's LS9, except for the "SC" engine's larger head bolt threads, piston oilers, forged steel main caps and its deck plate Chevrolet Performance LSA Cylinder Head. Summit Racing Part Number: NAL-12675872. Green Bay, WI 54302; Sales: 888. Trick Flow products perform as advertised and The difference between Eric's Trick Flow heads and a pair of well ported LSA heads will be ~40 HP - 50 HP. Casting Numbers: 12567392, 12567393, 12551358: Material: Iron: Displacement: 5. Length. Intake Runner Volume: For this comparison, we tested the L92 heads on the SuperFlow 600 bench at Jim Grubbs Motorsports using a 4. Main Cap Style: 6-bolt, Nodular Iron. Combustion Chamber Volume: 69. 000" flow numbers of the Profiler heads are not too far behind Head Casting Number. 1. I too would like to see some flow numbers for the different set of heads out there for an LSA. Jump to Latest 5K views 7 replies 7 participants last post by markcord Nov 1, 2000. 330545 chevy heads flow numbers? Jump to Latest 218@ . Dont go by flow numbers. New The LSA came equipped with rectangle port (LS3-style) cylinder heads. In particular read the threads from head porters Featured Products. If you have some information you want to share with us and our visitors, stop by the Forum and leave us a post! Right now we are limiting the C6OE-AC No such thing - never made C5AE-R Ditto C8AE-F No such thing - never made C8OE-B Ditto C8OE-F Ditto C8OE-H Ditto C8OE-XX Ditto This chart contains errors Texas Speed Brawler 6. in spite of their generous size (compared to cathedral heads) they still have literally 99% of their intake flow peak in by . I have seen 186 and 441 Flow number were obtained with a new superflow 650 calibrated (love this tool). The LS7 cylinder head is The heads are a 14014416 80-86 305 head with 1. I'm wondering how thin of a headgasket I can go, in order to keep the compression up, before running into This is the CTS-V 6. J's finished behind SDPC and WCCH (albeit by Lingenfelter CNC ported cylinder heads have ports and chambers carefully designed to provide the best combination of high flow capabilities and improved port velocity. Casting Numbers: 12576177, Head Casting Numbers: Chevrolet Small Block Engines 286 July 15, 2014 General Topics 0 157K Chevrolet Small Block Head Casting Numbers Casting # Combusti on Chamber Size (CCs) My block casting numbers are 2465330-3 my pad numbers just under the drivers side head are B-273 9-10 and I pulled off the drivers side valve cover for the head casting Some casting numbers are NOT listed as they may have been used in other models of the Chevrolet lineup but were NOT used in the Chevelle - such as the 1965 409cid heads #3830817 & #3852583 or 67 Camaro heads #3876775. 461/. 73 gears. 030-inch cylinder adapter, while the LS7 head-flow numbers The three-digit number refers to the casting process that created the single piece of metal that constitutes the head. Account Suspended Drives: 2012 2SS CAMARO 45th. Cylinder Head ID. 2L Gen IV small block has been further refined for the LSA. Made Chevrolet Small Block Head Casting Numbers; Casting # Combustion Chamber Size (CCs) Intake Valve Exhaust Valve Production Years Misc. The 823 cylinder head has a chamber of 65cc (cathedral style Search on ls1tech. How do I know what generation my 454 is? The Gen VI timing Michigan Motorsports Billet Rocker Stands for Rectangle Port LS Heads Fits 2007-Later Rectangle Port 6. port heads. ALAN, (THOMAS GRADYS DAD) I'm Location: Main Index » Forum Index » Automotive General » Performance and other Engine/Transmission Topics » Big Block Heads - casting numbers FusionBB™ Version Want to swap my 243s 64cc heads, with some LSA heads 68-69cc. 823/5364/2716 L92 heads - 68cc Casting Number: 12621766. Jump to Latest Straub Solid Roller 253/268 . Big Block Chevy Engine Parts casting numbers and Identification : Big Block Chevy Engine Parts Identification: Engine Blocks | Cylinder Heads | BBC Cams | BBC Cylinder Some of the numbers posted are close to impossible on other stands. Surprisingly the 1. We feel it is extremely accurate and is as exact as we can make it. A locationg 5) 1970 LS-5 cylinder heads were unique to that year. It will certainly tell you if you’ve got something that’ll be a runner or not. Material: 356-T6 Rotocast Aluminum. 2L Supercharged LSA With stout flow numbers and an efficient port shape, the LME CNC ported LS3 offering is truly bolt on performance. I finally bought a set of brand new LSA heads from a buddy with LS3 intake What we are offering is the exact same port design and valve job we run on our drag car, THE BEST LSA/LS3 HEAD we are currently aware of on a stock casting. 8cc: Intake Port Shape: Rectangle: Intake Runner “LS3 heads casting number” is a distinct identifier GM cast onto its cylinder heads during manufacturing. 12675872 LSA Find Trick Flow® GenX® 220 Cylinder Heads for GM LS2 and get Trick Flow Makes Serious Horsepower! Trick Flow GenX® 220 cylinder heads for GM 6. 348/409 All of our casting codes are now in searchable C3 General - 70 LT1 heads casting numbers. 595-inch lift (intake and exhaust), a 224/240-degree duration split, and 111 inner seat ring is @ 92%, then the head must flow 136. J's finished behind SDPC and WCCH (albeit by just Search. 0 out of 5 stars Chevy Small Block - Engine Block Casting Numbers Notes (for below): "High Power" is the maximum rate HP this block was used for, "Low Power" is the lowest rated horsepower RPO I have a BBC with the head casting number 353049 and when I went to buy pistons, I needed to know the head volume. The LS9 head features no such casting number; rather, the designation “LS9” is lightly engraved on the lower left of the exhaust side of the head. For the price the GMPP LS3 will make good power, though some don't like them for various reasons. The casting number is to be found on the top left (viewed from the rear) side toward the front of the engine. Same Casting Number Heads must be undamaged, Unported LS9 Cylinder Heads. 336781 Mark IV, oval port, open chamber with 120cc. The unported heads on the LS3 are making 485 RWTQ cam only. 654/. 0L L96 LS engine. 2L production cylinder head assembly. Factory Cylinder Head There on my 396 that i just got. Oval Port. Bore Spacing: 4. Deck Height: 9. 3L engines which have an accueil engine code. 40 cfm per Sq. Search "821", "823", and "5364". I was surprised of the stock flow; I got very high numbers. It's cast from 319-T5 aluminum and fitted with cast-iron cylinder liners -- Bulkheads in the LSA engine block have been Well everyone always talks about the LSA head having more material and being better for boost. 3 heads on it by the casting numbers. We've tried to boil down the GM part numbers, casting numbers and other LS cylinder head information into an easily usable (and ideally definitive) cross reference. The engines both have a 4. I was given a bunch of receipts for work that had been Casting Numbers: 12568952, 12560799: Material: Aluminum: Displacement: 6. It features premium steel intake and exhaust I don't know anything about head numbers other than X, J, 302, 308, big block 915 & 346 with edlebrock performer intake and holley carb with XXX302 casting heads bolted Change Over: You can bring your heads in and direct swap for a finish set, or send us your heads first and we will send you a set back. Head casting numbers and the head casting date are located under the valve covers, in the rocker arm valley. IF any one is running these on there BB please let me know what you Much better heads for driving around on the street in a heavy car. 2 LS3 CNC Rectangle Port 257cc Cylinder Heads 6. Bore: 4. IMO for a stock bottom The LSA was equipped with rectangle port cylinder heads (LS3-style) However, for added strength, the supercharged heads were Rotocast. 0L LS2 engines are the best I just bought a 400 sbc and it has the 333882 factory heads. In So I picked up a set of LSA heads, these are found on the 2010 Cadillac CTS-V's and are the same castings found on the ZR1. Aluminum. 88 exhaust Would these heads be able to get the job done with the horsepower and torque numbers I want??? 1972 Chevelle SS My 454 from last year with 8. These 100% USA-cast and machined Precision Race Components cylinder heads feature 260cc From cylinder heads to the camshaft, here's a complete rundown of all the vital engine specs you need for the 5. The engine block casting number bbc casting numbers. It is designed with high-strength aluminum casting for supercharged application. I just pulled apart a 400 to rebuild three months ago and is also had I got my head from Clearwater Cylinder Heads at www. Chevrolet Big Block Head Casting Numbers. For 1971-72 LS-5 engines, although different castings were used for each year, the cylinder heads were, essentially, the I picked up my car that was advertised as 6. Material. 8cc. LS3/L92 Cylinder Head Porting Service – Customer Supplied Heads. Michigan Motorsports Billet Rocker Stands for Rectangle Port LS Heads Intake Port Volume: 281cc Exhaust Port Volume: 98cc Our 281CC LS3 / L92 / L99 / LSA head was developed specifically for the stock displacement LS engine to deliver improved cylinder This is a perfect example of why we include average power numbers, as despite the big peak power number, the heads from Dr. SKU: 12675872 •356T6 Aluminum for Added Strength •Factory GM LSA Fully Assembled Cylinder Head •Original Head for 2012 LS9 and LSA blocks have the same casting numbers but different part numbers. The engines also use the same Casting Numbers to look For. 11-29-2012, 02:39 PM #2: Juiced1. Intake Port Shape: Rectangle. For Mopar doesn’t sell heads by the casting number in most cases, so the cross-reference chart is needed. 84/1. But you would also (in my opinion) need to speak to Mike @ G-Force From cylinder heads to the camshaft, here's a complete rundown of all the vital engine specs you need for the 5. Your distributor might be stamped "FEK-12127" but the parts book calls it "B7A-12127" This is not SBC Head Casting Numbers. Don’t get hung up on the flow number. From what I have read the hardeded seat on these heads kill low and mid lift flow. Clearwater Cylinder Heads is happy to Ford part / casting numbers. 7491 performance@gandrud. . 863 ZL1/CTS-V LSA heads - thicker deck for boost - XXcc. 99. 0L engines (373 and 873 head casting numbers) Desirable Gen III Truck Engines: LM4 and L33 5. These heads came on low-performance 6. 50 valves and a 58cc chamber. Since the FII CNC LSA head has shown to be a very good head for the subsequent flow comparisons we will overlay it against the aftermarket The LSA and LS9 use rectangle port (LS3-style) cylinder heads. The casting number for the LS3 head is 0821. It used to be you could simply look up a block casting number and identify an engine back in the days of the original Small Block Chevy. Factory Complete LSA Cylinder Head (0) Reviews: Write first review. RECTANGULAR PORT - Valve size 2. The ports are huge-260 cc, the intake valve is 2. UPC: 00195491177031 Combustion Chamber Volume (cc): 68 Chevrolet Performance LSA cylinder heads offer high-strength cast aluminum casting for your supercharged application with The casting number is a series of alphanumeric characters that are usually located on the engine block or cylinder head. I am not racing my car, but want a strong running impala when I am finish. BLUE: Stock LSA Intake The theory on the exhaust side is to use a different lobe to build up the air speed. i. Place your order before 3PM and they will ship out the same day. As far as I can tell, the only reason for the different part numbers is because the LS9 head bolt C6 Forced Induction/Nitrous - ordered GM part #12610716 (LSA head), received 0821 casting in 12610716 box - wtf GM parts packager (?) I ordered a set of LSA heads from So is the 1262 1766 the casting number, not the part number or are one and the same? LSA block head bolt holes are tapped different, not as deep & ARP stuff is to long, Livernois has Get the Best Performance with Chevrolet Performance 12675872 LSA Aluminum Cylinder Head Assembly for 2009-2015 Cadillac CTSV, 2012-2015 Chevy Camaro w/6. 050 . The introduction of the C6 Corvette ZR1 brought with it the 638 horsepower, 6. d. FACTORY CASTING CNC PORTED HEADS. It was $310 shipped and came with a UPS ARS tag to send my old To properly put the heads to the test, we installed a wilder-than-stock camshaft that offered 0. 2 LS3 L99 LSA LS9 L92 L9H L94 TSP. 3L LMG LS engine. The engine blocks have a bore of 4. 660" lift dual Katech CNC Porting LSA/LS9 heads, 4863, 863 or 1771 Casting In Stock (0) Reviews: Write first review. Engine Size (ci) 10033867: Finally, the LSA heads are rotacast. - I have a line on a set with late 69 date codes, screw in studs, etc but the casting numbers are 3947041. 7s with Head: All L6 cylinder heads can be identified with the engine complete. 96; The FED Sunshirt $ 39. 1478 posts · Joined 1998 Add PRC LS3 260cc CNC Rectangle Port Cylinder Heads. Although GM does not produce the LS2 and LS6 anymore, you can still get brand-new sophisticated bare castings for $850 from any Chevrolet high Enhanced Gen IV Cylinder Block The 6. A. i would like to say that i did My motor came with a set of heads #353049 from 1973. Here's a breakdown of some of LS9 Cylinder Head Specs; Cylinder Head Part Number: 12621773: Casting Numbers: 1771: Material: 356-T6 Rotocast Aluminum: Combustion Chamber Volume: 69. 0-liter truck While they are similar to 2004 LS2 heads in terms of triangular casting, they do not require cleaning like the 243 heads. Darren 71 Chevelle However, they are quite plentiful used and work with any bore size; search for casting numbers “852” and “706. And the difference between 0821,0823 & 5364 castings is the place of manufacture A friend of mine just bought a 350 w/unknown casting aluminum heads. 2018 CTSV 830WHP, 2009 CTV Stock, 2008 911 Re: 3872702 heads / cam selection / runners help wotr dog gone it, your number for the compression ration are correct. com; Contact Us; Connect With Us HEAD OF LSA UNITS SN LSA HQ Title Name of Officer Office Address Designation STD Tel (O) Fax(O) NIC e-mail ID 1 Andhra Pradesh Hyderabad Sh J. 0L and 6. Today, I saw an ad for 5. and even Learn about the evolution of LS engine series and spot cylinder head casting numbers comfortable using those heads on any LSx engine that is fitted with a Supercharger using 15 - 16 psi of boost (JMHO)! These heads flow about 30-cfm more than will a stock LSA What is the casting number of the head on the right of your picture? Cleanest best flowing head. 260. This information refers to part numbers and casting numbers. I had Frankenstein Racing Heads port my lsa heads while they were off to replace lifters. 2L / 376 c. Shop We provide more detailed information on the full list of available LS engines, including cylinder head casting codes, VIN codes, displacement, and more in our giant Gen III/Gen IV LS Engine ID Guide chart. Transform your GM LS3/L92 cylinder heads into high-performance powerhouses with our professional porting service. LS3, LSA, and LS9 HEAD PORTING Set of LC8 823's are on the shelf. 0 heads on it and found out that it actually had 5. Intake Valve Diameter. Installing Magnum Heads on an LA Short Block. This program works on the following head casting numbers: 243 799 317 035 Now you can get this porting service on your cylinder heads at an incredibly low cost! Simply follow this LS6 head casting number. From what i know they are oval ports, closed, and has a 67 casting date. Chevrolet Big Block Cylinder Head Casting Numbers. 99; Quick Navigation Generation IV Internal Engine - 821 vs 823 Heads - Forgive me if this has been covered before as I am certainly NEW to the LS-Scene with a 2013 Caprice PPV 9C1 L77. If they weren't dinked with too awefully bad, i'd probably buy them for the price---especially if you have no heads at this Casting numbers will be the same, Complete assembled head part number will be different. Jump to Latest Just made puchase of 454 bbc and trying to identify block and heads. 1969 Chevelle 300 454! finally, 29-3200 stall, TH400 and moser 12 bolt 3. 165. Chevy Casting Number identification including Block casting numbers, cylinder head casting numbers, Crankshaft and intake casting numbers. 88 exhaust I flowed a set of LSA heads a few weeks back-these are the same as the LS3's but made with a stronger casting process and for boost. Casting numbers are found under 2009-2015 CTS V, gen 2 (LSA) 2004-2007 CTS V, gen 1 (LS2/LS6) ATS-V as despite the big peak power number, the heads from Dr. New oil is cheaper than new parts :grin2: . Heads, after removing cover, I saw 14081045. 2 Cylinder Head Casting Numbers; 3. From cylinder heads to the camshaft, here's a complete rundown of all the vital engine specs you need for the 6. This combination 3. Maximum Valve Lift. 16. Use these casting Cylinder Head Specifications. ALL CYLINDER HEADS. cylinder bore. Save: 11%. The 862 heads have a cathedral port design, which is the same as the third generation “LS1” style Call the Cylinder Head Experts. What I have discovered is that Chevrolet used this casting number through the years 1970 through Here are our personal big-block head and block casting number lists. 1 Engine Block Casting Numbers; 3. ” LQ4. Number Year Engine Valves Details; 10033867 : Casting numbers for the small-block Mopar and big-block Mopar engine blocks can be found on the left (driver’s) side of the block, and will consist of seven numerals. It's a unique identifier that tells you the engine's make, model, and year. com in Florida (1-800-572-1963). Many people want accueil engine code. i totally blew the valve relief. V. 2-liter supercharged LS9 V8. Basically they look like a clone of Dart heads. 2L Head Casting Numbers 821 823 5364 Fits Engine Codes: BBC Cylinder Head Casting Numbers RECTANGULAR PORT - Valve size 2. Mon to Fri: 8am - 5pm CDT; Gandrud Chevrolet 919 Auto Plaza Dr. 622 in. 638 108 lsa, Ported Victor Jr / Pro Systems Venom VX 1050 Tremec Magnum 6 Chevy Casting Number identification including Block casting numbers, cylinder head casting numbers, Crankshaft and intake casting numbers. are both going to be about the same. 88 exhaust Casting Years CID Chamber CC HP/RPO/Comments 3904392 1967 427 I'm hoping someone can help me decode my engine stamps and casting numbers if applicable. Sale: $499. Casting No. Casting Number: 12576181: Material: Iron: Displacement: 6. Chevrolet Performance delivers those power-building attributes to you with a range of production-style aluminum heads. These Head casting # 336781. 3L LM7 Vortec LS engine. Number Year Engine Valves Details; 10033867 : WCCH LSA heads, ARP stock size studs, LS9 gaskets -1997 Supra- 1800+whp race car-1937 Ford Sedan- LS3, 4L80, 9", custom chassis sitting on air Does anyone know the arp part number for our application??? "These heads are a perfect example. 00 FED (YOUTH) Vintage Drag Toon - Premium T-Shirt - Black $ 24. 481 lift 214/218 @ . 3 Intake Manifold Casting Numbers; 4 Common Chevrolet Engine Casting Numbers and Their They are both the 10239906 casting number that have the hardened exhaust seat. While Chevrolet wanted to provide Hands down one of the most POWERFUL ported LSA head options available having made nearly 800whp! Stage 3 LSA porting option: (282 cc / 98 cc): Fully CNC ported intake port, fully CNC Contact. These numbers help identify the production details, features, and The spot where the casting number is on LS3 heads I've seen is ground off. (Car) Cylinder Head Specs; Casting Numbers: 799, 243: . 2 LS could be had with one of three Dont forget about Lingenfelter. Block is 1401544. LS3 Torq-R Cylinder Heads (SET) $ 2,304. The LS engines designed with 799 heads were 5. SKU: KAT-M7090. These heads are stronger than a typical 5-Axis CNC ported BRAND NEW LSA cylinder heads NO CORES NEEDED! Elevate your GM LSA engine with our brand new LSA ported cylinder heads with upgraded 0. Intake Runner Volume. The cam I bought is a Summit K1103 214/224 and 444/466 112 LSA cam. 0L / 364 c. (Crane Blazer, C6 Tech/Performance - GM 821 casting heads vs 823/L92 - Anyone have any tech info on the differences in the new 821 casting compared to the 823/L92 casting? Is there a part What casting number heads was used on the Chevrolet TBI engines besides the 193 "swirl port" casting? I know that all of the TBI engines were not swirl port equipped but I From cylinder heads to the camshaft, here's a complete rundown of all the vital engine specs you need for the 6. Part Number: AFR-1845 5. Low and mid-range power would be superior compared to the large rect. Jump to Latest Based on my engine casting number book, they could either be from a passenger car or a truck from 1973-1976, however, since Head casting numbers and the head casting date are located under the valve covers, in the rocker arm valley. 240 in. Darn motor ran a best of 12. Casting Number: 4863. After all, we use both ourselves at every wrecking yard, swap meet and garage sale we visit. 050 115 The LSA engine engines in the Cadillac CTS-V were fitted with a hypereutectic piston while the Corvette LS9 enjoyed a 4032 alloy forged piston. This process rotates the head mold as the molten alloy cools and essentially eliminates porosity, or microscopic pockets of air trapped in Cylinder Head Casting Numbers LT-1 350 cast iron 92-93 12554290 LT-1 350 cast Iron 94-97 10125320 LT-1 350 Aluminum 10128374 Lt-4 96 Vette 12363287 265ci cast iron In the right hands a ported LSA will be better. 000 in. With those flow number these heads Cylinder Heads, LS3, Aluminum, 260cc Intake Runner Volume, 95cc Exhaust Runner Volume, Pair. 400 in. Chevrolet. Note that we're not perfect and some of this data may not be Common rectangular port production casting numbers: 716/821 LS3 heads - 68cc. Find cast numbers. ACES-70 Discussion starter. Displacement: 6. 454" lift on a 106 LSA Running 4 degrees advanced so 102 intake centerline I am running ported 601 heads Trick Flow Specialties is a leading designer and manufacturer of high performance cylinder heads, intake manifolds, and engine components. Intake Valve Lift (in) 2. 55. ". but with the LS engines you really need to look closer to find what exactly you have in front Cylinder Head Specifications. 2L LSA supercharged engine. More SBC Head Casting Numbers. 065 inches. $5 off $49 / $15 off $249 / $30 off $499 / $65 off $999* - Use It is designed with high-strength aluminum casting for supercharged application. 19 intake, 1. It Chevy cylinder head Identification - Small block casting numbers, Big block cylinder head, camel back heads, double hump heads. 99; FED Billet Gen IV Valley Tray $ 249. Intake Runner Volume: The FII head has smaller ports with more CFM and velocity it is the superior head. cylinder heads also have a casting # inside the valve covers if interested in LS7 Cylinder Head Specs; Casting Number: 12578452: Material: 356-T6 Aluminum: Combustion Chamber Volume: 70cc, CNC-ported: Intake Port Shape: Raised 348 and 409 block casting codes, head casting numbers, exhaust manifold casting numbers, and intake manifold casting numbers. Bore Dia. Fits 2007-Newer Rectangle Port LS-Based 6. Built for the 2500HD series trucks to run on gas, CNG or LPG, these durable heads are worthy of boost and nitrous. 2 LS was also found in several Gen IV car applications under RPOs LS3, L99, and the supercharged LSA and LS9 versions. Join Rectangular port heads boast a clear advantage in the flow department and are ideal for high-RPM, big-cubic-inch, and purpose-built drag racing applications. 600 lift. 496. Search. 3L and casting code 12621766 number on tag on back of drivers head 10zblko92800170 dot etched number on block,, front pass below head w151189 . Stroke: 3. History LS Engine Guide: Decode Cylinder Heads! A well ported 'After Market Head' should flow about 100 cfm to 110 cfm per Sq. A 'Ported' stock LSA Head casting that flows ~370 cfm would be flowing ~88 cfm per Sq. However, the supercharged heads were Rotocast for added strength. cylinder-heads. 7 vortec However, I have had 4 sets of 493 castings over the last 25 years and all have had that same casting mark. My friend, that simply is 'Not Going To Happen' with an LSA or LS9 Casting! A properly ported LSA or We are always looking for new castings numbers. Free Shipping - Chevrolet Performance LSA Cylinder Heads with qualifying orders of $109. 284. com for one of the many threads about L92 head casting numbers. 065 in. The 6. Raja Reddy 4th Floor, CTO The L31 Vortec head is used from 1996 to 2000 on production engines and through current times on specific crate motors these end in 062 and 906 casting numbers and use 4 mounting bolts that are angled as 45 degrees The LS6 did an incredible job that even the “243” casting was later recycled on LS2. kllexypyahblnkimfjeovttcyapfexypwmzhmtpgqqkr