Apr 16, 2022 · I have LS 243 heads, fresh valve job. I'm trying to install the TFS 2500287P spring kit. The spring install height is 1.8". I have the BT spring micrometer and I'm getting measurements all over the place with it. And the spring perches are varing up to +/- .0015, from pearch to pearch (measures with a digital vernier).Exhaust flow at .600" - 180 (241) / 183 (243) The 243 heads have a D-shape exhaust port that improves flow and came with higher lift valves springs. Both heads came with 2.00" intake valves and 1.55" exhaust valves. To my understanding, this is all the difference. Last edited by R6cowboy; 02-26-2011 at 01:52 PM.Jun 5, 2010 · Price wise both companies are very close to each other. TEA Stage 2 Heads $1320 w/ 2.04/1.57 valves and dual springs. AI CNC Heads are $1245 w/ new stock valves and dual springs. It seems like the TEA has an obvious advantage in flow with the 2.04 intake valves but AI does not have any options for larger valves on their website.Hey all, I'm planning on doing a ported fast92 and getting my stock heads worked for optimum power and bang for the buck. With that said, I really don't... in this thread in this sub-forum in the entire site. Advanced Search Cancel ... Who should work on my 243 heads? 1338 Views 13 Replies 12 Participants Last post by TheGoatHooker, Aug 20 ...chevymastermind said: I have a set of Chevy heads with a casting number of 333882, with 1.94 Heads, i am hoping to make 350-375HP with them. the engine is a 350 Steel crank, 4 bolt main, 9.5:1 compression ratio with these heads, comp cams .480/.480 lift with 230/230 Duration at 0.50, 600cfm edelbrock carb, Performer RPM intake, headers with ...Originally Posted by silverz28camaro. the 853 heads are stock from 98-00, then they had the 241 head which was pretty much the same head. If you find a 243 head then you are in business they are the ls6 head. If the 853 you have now are ported then you may have something. Take pics of the intake ports and post them up.Sep 28, 2011 · I would think a 243 head is a 243 head, I think I read that the 243 was used on the LS6 Z and all LS2 motors had the 243 heads. Mr.Bill Reply Like 09-27-2011, 08:43 ...The 243 head came on the more powerful LS6 engine from 2001 to 2006, and was used in C5 Corvettes. Later engines like the truck-spec LQ9 and LQ4 used the exact same port design as the LS6's 243 heads, but had 6 cc larger combustion chambers.Identical heads would be the 799s. They don't have the cult following of the 243s, so they're often found cheaper but they're the same head, just cast at a different plant. The only difference in the "regular" 243 from the LS6 243 is that the LS6 version had lightweight valves and special springs.Nov 24, 2021 · Chevy 706 Heads come with all new stainless steel swirl polished 2.00 and 1.57 valves, new springs for up to .650 lift, new retainers, spring seats, and valve seals. The heads are washed, disassembled, pressure tested, and all valve stems have been replaced as per requirements. Scroll down to learn more about 706 heads. Chevy 706 Heads- …My plan is to use my 243 heads and intake on the l92. I’ve got a new gmpp 12638427 cam as well as a 05 lq4 cam.Not looking to make huge HP, just looking to optimize fuel efficiency and maybe nice exhaust sound. also don’t want to loose lo to midrange performance. Between 400-500 HP would be nice. any thoughts or …No modifications to do a head swap, but if both are stock untouched heads the 241s have a 66cc chamber versus the 243s 64.5cc chamber. A slight bump in compression, but it shouldn't be an issue. I believe after 07, all 5.3 engines have 243 heads. Now that you're swapping heads, you should consider getting them ported beforehand. KerryFactory has the 862 heads. I’ve been offered a 5.3 block with 243 heads on it for $300. Would the stock 243 heads work better on it than the 862 heads? Obviously they need to go to the machine shop to be looked over but without any alterations to the stock form, which is the better head? Engine is stock other than cold air intake.What did LS 243 heads come on? Sometimes referred to as the cathedral port design, the 243 heads were developed by GM engineers in 2001 and featured prominently on LS6 engines until 2006.Initially made for C5 Corvette models, these powerful heads soon found their way into other engines including the truck-spec LQ9 and LQ4 versions both of which had larger combustion chambers (6cc) than their ...The real advantage to the Gen IV engines are the cylinder heads. The 243/799 heads have cathedral ports with improvements destined for the LS6 Corvette and later the LS2. They also had larger 2.00 ...This listing is for a rebuilt GM 5.3 5.7 or 6.0 liter V-8 cylinder head casting 243 only you must have an exchange with the exact same casting number. These heads come on GMC and Chevrolet trucks and SUV's. For other models see our store listings. This head is completely rebuilt. It has been pressure checked for cracks and resurfaced.Receive notifications when cylinder heads are in stock and ready to ship. First ... Leave this field empty if you're human: FED LS1/2/6 Cathedral 243 Stage 2 $ 2,784.96. Beautiful set of 243’s are on the shelf and ready to ship. The heads are assembled ... o Valve Guide Clearance – Your FED Heads come with proper guide clearance for ...Dec 27, 2022 · What did 243 heads come on? To begin, the LS6 engine was first introduced in 2001 and used until 2006. It came equipped with 243 cylinder heads which were initially designed for C5 Corvettes. However, the popularity of the LS6 spread to other applications such as trucks with the LQ4 and LQ9 engines.stock 243's are worth about 15 rwhp, with cam and headers maybe 20-25 rwhp at most. i was in the same boat decided to hold the 243's until next yr or longer and send them to cartek for a 2X job and mill then then they will be worth about 40 to 50 rwhp. somebody else on the forum will come along and give you some more advice from experience with stock 243's. good luck btw what cam will you be ...The LS3 head at 265 cc of volume compared to 214. cc for the 243, has much less air velocity at low lifts and low rpms. Now. GM also put the LS3 heads on an engine with 30 more cubic inches; but with an intake runner volume equal to the old big block oval ports, they really seem to shine on 427 cid and larger engines.Jan 18, 2014 · It's a 2004 A4 LS1. Lots of good info here. I can't seem to find much on these 843 heads except they're older than what comes with my car. A friend of a friend is looking to sell them to me for $1000. He said they're used off an older corvette, cnc'd on intake exhaust and combustion chambers, new stock valves with 3 angle valve job, ls6 yellow ...Engine Technical. Engine Tech And Modification. LQ9 build cam suggestions. I just got my 4x4 T56 swap completed and now I'm planning a nice NA build. Through research I've found that the 243 heads and TBSS intake are a nice combo with CR around 11:1, and basically my whole setup hinges on the cam selection.The 806 heads are literally 1st gen heads, have a perimeter bolt pattern for the valve cover. Which means you need that cover and IIRC the coil packs bolt directly on the cover vs a bracket that holds the packs together. Flow is meh even when ported. You should look for 317 or 243/799 heads with the emphasis on the later for NA builds, if going ...We may earn a commission for products purchased through links on this pageMar 26, 2012 · From how I understand it to work...and I'm no expert... 317 heads are designed for a 4.000" bore motor. Your LS1 is a 3.900" bore motor. Therefore, you'll need a thicker gasket on your heads. Stock heads are 67cc and you are going to a 72cc. This is going to drop your stock 10.5:1 compression down some.But these heads also saw duty on some 1962 and 1963 full-size Chevy passenger cars with the 300 hp 327. Those produced in the Tonawanda plant were exclusively used on those bigger cars. Flint heads saw duty on both full-sizers and Corvettes. The heads are quite easy to identify, as they sport an “X” underneath the #1 …706 heads are very affordable. 706 heads are plentiful and easy to find. 706 heads have smaller chambers, so you don't lose compression. 706 heads are slightly superior to 862 heads due to how ...Aug 31, 2020 · The 806 heads are literally 1st gen heads, have a perimeter bolt pattern for the valve cover. Which means you need that cover and IIRC the coil packs bolt directly on the cover vs a bracket that holds the packs together. Flow is meh even when ported. You should look for 317 or 243/799 heads with the emphasis on the later for NA builds, if going ...The 241 castings feature 205cc intake ports, 70cc exhaust ports, and a 2.0/1.55 valve combination. The hot factory heads would be the LS6 (243 castings), but even the stock LS1 heads can be made ...Last updated on 05/06/2024. The LC9 engine is a 5.3L, Gen. 4, aluminum small block engine used in GM trucks and SUVs between 2007-2011. For marketing purposes, it was also known as the Vortec 5300. The engine specs and information listed here is for a stock LC9 engine. Mechanically similar, General Motors’ LS and LS-based …DualQuadDave Discussion starter. 1019 posts · Joined 2017. #1 · Oct 7, 2018. Hi all, I am looking for info/opinions on doing a big valve 243 head. I have researched and about 2.04 is max size for stock seats. I have a motor that I want to do a 2.08-2.100 valve and shoot for 330-340cfm int flow. Motor is 4.005 bore, .620 int lift.Chevy 706 LS Heads are high-performing cylinder heads that offer enormous power at an incredible price. They are the most affordable and most effective remanufactured cylinder heads that can be used for a 4.8L, 5.3L, and even 6.0L LS engine build. Their thin cross-section depicts a high-velocity and smaller-volume runner design with an ...Tinnitus is the perception of sound originating from within the head rather than from the external world. More about tinnitus Try our Symptom Checker Got any other symptoms? Try ou...Are 243 heads cathedral Port? Usually, conventional small-block heads did not flow nearly as much air as the best factory cathedral port heads.The 243, 799, and 317 castings of these cathedral port heads could flow up to 250 cfm which was a major improvement over what preceded them. But the LS3 heads took this concept even …Compression Ratio Calculator - Wallace Racing. 3.622" x 4.00" / 6.098 rod length / 9.240 deck ht. / 0.008" out the hole / 0.052 gasket / -6.7 cc dish / 4.000" head gasket bore / and either 71.06cc for 317 or 64.45cc for 243's. Note if you do run 243's on the LQ4, the piston raised ring around the dish has been known to interfere with the ...706 heads are very affordable. 706 heads are plentiful and easy to find. 706 heads have smaller chambers, so you don't lose compression. 706 heads are slightly superior to 862 heads due to how ...431 posts · Joined 2019. #9 · Jan 5, 2021. 706 heads out perform all others on a 4.8. Throughout the entire normal rpm range. It's not all just about flow. Those larger flow numbers from other heads are misleading. Yes they flow more than 706 however, only beyond 6000rpm. 706 heads are the best for the 4.8.Intake and Exhaust Ports. The intake and exhaust ports on the 243 heads are larger than those on the 799 heads, which allows for more air and fuel to enter the engine. This can result in higher horsepower and torque output. However, the smaller ports on the 799 heads can provide better velocity and airflow at lower RPMs, which can be beneficial ...The intake ports on 862 heads flow slightly less than the stock 243 heads that come on most 5.3L LM7 engines from the factory. However, the 862 heads have a smaller chamber size, which raises the static compression ratio by approximately 0.5 point on otherwise stock 5.3L engines. This can improve the power output and durability of the engine.DESCRIPTION Professionally rebuilt 5.3 Chevrolet / GM cylinder heads. These cylinder head's casting numbers are: 243 ONLY! THESE HEADS ARE THE SOUGHT AFTER 243 CASTING NUMBERS ONLY THIS IS FOR A PAIR HEADS! DETAILS Heads are thoroughly cleaned and inspected Pressure tested to ensure no cracks or leaks Guide work performed / replaced with new guides as necessary Valve job / performed on Serdi ...chevymastermind said: I have a set of Chevy heads with a casting number of 333882, with 1.94 Heads, i am hoping to make 350-375HP with them. the engine is a 350 Steel crank, 4 bolt main, 9.5:1 compression ratio with these heads, comp cams .480/.480 lift with 230/230 Duration at 0.50, 600cfm edelbrock carb, Performer RPM intake, headers with ...So I have been playing around with some 243 heads, ported them to 225 cc on the intake port left the intake with a carbide finish and ported the exhaust to 83 cc stock the heads are 215cc/75cc. I just did a standard clean up bowl porting remove the rocker boss trim down around the guide valves are 2.02/1.57 cheapo stainless valves I was hoping ...The seat insert itself is 2.02", so going bigger than that would be pointless without swapping out the seats. To use a 2.04" valve on a stock seat, you would have to cut the seat small at 2.02" so it is still on the iron seat, which I don't think is any better than just using a 2.02" valve. If the seat is cut bigger, some of the valve contact ...C5 Tech - LS6 valves vs stainless aftermarket in 243 heads - Curious if you guys running 243 heads keep the stock valves or replace them with aftermarket that might help flow. Looking to pick up a set of 243 heads needing hardware and work them over myself. I imagine the LS6 valves are not undercut like the stainless...The 243 heads come with 1.7-ratio rockers responsible for opening and closing the intake and exhaust valves. The configuration is different from the 1.8 ratios found on most other LS heads. ... Ported 243 heads can still be used today due to their many highlighting features. Cylinder Block. 243 heads. The cylinder block is the foundation of the ...But, the combustion chambers are bigger than the 5.3 heads. You need to mill the 243 heads about .020" to keep the compression ratio the same. 2004 torrid red with red interior A4 GTO (1 of 499) TR-230/236 cam/TEA ported Trick Flow 215 heads/4" CAI/100mm MAF/ported FAST 90/Kooks/Magnaflow.Some early LS heads from 98-01, both the 853/806 LS1 and the 706/862 5.3/4.8 had the casting notch. The notch disappears sometime in 2001 but nobody is sure. Only way to verify is to physically look for the notch on the gasket surface. If the heads have the notch, you must use the early graphite gaskets.Head History. The selection list is basically rather thin for today's performance engines. The earliest 265 and 283 small-blocks relied on an iron Power Pack head that featured 58-cc chambers and tiny 1.72/1.50-inch valves. The bigger heads to follow were the "double-hump" heads championed by the mid-'60s 327 engines.NEW GM LS 243 HEAD - 4.8L, 5.3L & 6.0L. $349.99. Generation III V8 cathedral intake port cylinder head. Casting 12564243. For truck, van, SUV and perfomance applications. Used on LS6, L33, L20, LH6, LY5, LMG, LC9,LS4, LH8, LS2, LFA, LZ1 engines. Add to Wishlist. Skip to the end of the images gallery. Skip to the beginning of the images gallery.The 241 heads were used on 5.7L LS1 applications and are considered by many to be just a minor step up in performance from the 706. In terms of peak flow, the …243's are LS6 heads. Those are usually the choice for porting. 241 is the stock LS1 head. Can be ported but again most go with a 243. ... Come join the discussion about performance, modifications, racing, restoration, classifieds, troubleshooting, maintenance, and more!These large-runner heads have a 12-degree valve angle, like stock, and are compatible with factory LS7 rocker arms and stands. The heads can accommodate 1.625-inch-diameter springs, and several are available. A 4.125-inch-or-larger bore is required. Base price is $1,130 each, fully assembled, through Summit Racing.LS1 LS6 243 / 799 Aluminum Cylinder Head CNC Porting Service ( Customer Supplied Bare Heads ) CNC Ported LS1 243 / 799 Cylinder Heads, Customer Supplied Bare Casting heads. $599.95. Options. Valve Job with new Valve Guides + $400.00. Resurface for MLS Gaskets + $150.00. Cylinder head Assembly + $150.00.Aug 6, 2020 · The 243's have bigger valves which do better on 4.0" and larger bores. On the smaller 3.898/3.78" bores of the LS1/6 & all 5.3/4.8's the 706 are very decent. On a 4.00" bore of an LQ4 though it is splitting hairs. On the same cam, on the same engine, the heads are going to perform within +/- 5hp/5tq of each other, it is almost meaningless.The factory-built motor dished out about 430 horsepower right out of the gate, and the cylinder heads play no small role in that impressive output. The LS3 heads hit the flow bench. The LS3's 319-T5 aluminum alloy cylinder heads use 2.165 in (55.0 mm) intake valves, 1.59 in (40 mm) exhaust valves, and a 15 degree valve angle.The 3927041 heads did not come on the 302. They are basically the same except for the casting symbol on the front. The 041 head has a triangle and the 186 head has camel back humps. The 186 head is the correct head for the 69 302 engine. Team Camaro Gold Member #14I am beginning to find and spec all the parts I need to start the 6.0L LS swap for my 2002 Silverado. A significant key to the success of this build is the c...Factory has the 862 heads. I’ve been offered a 5.3 block with 243 heads on it for $300. Would the stock 243 heads work better on it than the 862 heads? Obviously they need to go to the machine shop to be looked over but without any alterations to the stock form, which is the better head? Engine is stock other than cold air intake.Great 799/243 heads all the surfaces were true and the valve job was perfect. Read more. One person found this helpful. Helpful. Report. Ron R. 5.0 out of 5 stars Perfect fit. Reviewed in the United States on February 2, 2023. Verified Purchase. Exactly what I was looking for. Read more. One person found this helpful. Helpful.. I know 243's are good but didn't know if 862's are any good wAre you looking for a rental property near you? My car is an ls2 of course, but with stock injectors, fuel pump, and stock catback exhaust, and with stage 2 ported intake, tb,hpe 243 heads, megadeath cam, and slp underdrive pulley with lpe cai did 450 rwhp. The injectors were at 124 percent duty cycle, and we were losing fuel pressure above 6300 rpm.Patriot Performance 2033: My run a total 24 degrees of timing with 93 octane. These heads provide up to a 65 cfm improvement over stock OEM versions. The 59cc chambers (achieved by milling), will increase the compression on a stock LS1 from 10-1 to 11-1. Based on other modifications, gains of up to 40 rwhp can be expected. If .600 or higher, go with Pac 1518s. Plenty of g Welcome to Chunyun, the time of year in which 3 billion Chinese travelers head home for the Lunar New Year. In the spirit of the long-standing Chinese tradition of spending the Lun...Jul 16, 2007 · Thanks. 853 and 241 are basically identical. 853 was used on 99-00 LS1 engines. 241 was used on 01-04 LS1 engines. They both have a 66.67 cc combustion chamber (10.1 CR), 200cc intake runners, and 70cc (round) exhaust ports. The 243 head is the 01+ LS6/LS2 head. The LS 243 Cathedral Port cylinder heads are renowned...
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