The 243 heads are, as far as i know, the best factory casting to go with based on the chamber design. Even though our stock heads flow very close to them(or the same), the 243 heads are supposed to have a quench pad in the design and offer better compression. The info i have lists the 243 heads at 65 cc so with the stock gasket you would be ...For the sake of mass production, the production Gen III V-8 cylinder heads were designed to fit the smallest-bore Gen III V-8 engines--the 4.8L and 5.3L, 3.780-inch-diameter cylinder bore SUV and ...862 heads: These are also compatible with 5.3 engines, similar to 706 heads. However, they offer slightly less power potential. 243 heads: A popular choice for LS enthusiasts, they provide higher power gains when matched with the right cam. Cam swapping with 5.3 engines typically benefits from using LS3-type springs. These springs improve valve ...862 s Vs 243 s..... So what the difference between some milled 862s and some stock 243s? Also how big of a difference would the 243s and a nnbs intake do on a …Jul 10, 2022 · You are much better off with the 706/862 heads from a compression standpoint. Also, the port velocity on the 706/862 head is much better than the 799/243, which will help you with the small bore of the 5.3. The 706/862 respond very well to a light runner cleanup and a good multi angle valve cut.Last Updated on Aug 16, 2023 By Paul Lucas. There are three main differences between 241 and 243 heads. The first is the size of the combustion chamber, the 241 has a 67 cc, and the 243 has a 65 cc. The second is the port shapes. The 241's oval-shaped port has a 200 cfm intake, and the port on the 243 is D-shaped and offers better flow.RPO L99 and LS3 cylinder heads are aluminum with 68cc combustion chambers, rectangle intake ports with 257cc runners, D-port exhaust with 87cc runners, 2.165˝ intake valves and 1.590˝ exhaust valves. These heads can be CNC-ported to improve on flow and milled for higher compression. These heads are almost the same, but the L99 heads used a ...By Paul Johnson - March 9, 2016. This article applies to Chevrolet Camaro and Pontiac Firebird (1998-2002), as well as all LSx engines. The cylinder head (or "head") has several main functions. Its first order of business is …But as for the 5.3/4.8 heads, they used the same cylinder heads, identical. The only difference from the 706 and the 862 heads, are the way they are made. The 862 heads are sand cast, and the 706s are SPM (Semi permanent molded), but with just a bit of machine work, the difference between the two is null.You are much better off with the 706/862 heads from a compression standpoint. Also, the port velocity on the 706/862 head is much better than the 799/243, which will help you with the small bore of the 5.3. The 706/862 respond very well to a light runner cleanup and a good multi angle valve cut.The 862 and 706 casting Cathedral-port cylinder heads can be CNC-ported to flow close to the aftermarket heads. With a bigger cam you can mill the heads for a little over 10:1 compression which runs on pump gas. ... had two head bolt lengths vs. three on the earlier engines. ... the 243's (or 799's with their similar chamber and flow) would ...The valves on LS3 heads are designed to be larger than those on stock LS heads to improve airflow, leading to increased power output. Standard valve sizes for LS3 heads include 2.165 inches (intake) and 1.590 inches (exhaust). However, it's not uncommon for LS3 heads to feature even larger valves. For example, some aftermarket LS3 heads may ...The 2007 year had three 5.3L motors offered. The 2007 Classic (still a NBS) had the 5.3L with either the L59 (flexfuel version) or the LM7. The 862/706s are on the 99 and up 4.8/5.3L motors. The only difference about the L59 motor was the injectors. 2005 and up motors had the factory electric fans and electric TB.The 862 heads from the 5.3 aren't gonna be the best thing for the LS2, but they will work. I would spend the few extra dollars to find some 243s at least. Reply With Quote. ... 799/243 heads on a LS2/LQ9 put you at 10.9:1 compression. No where near pump gas limits. Don't waste your time with those junky 5.3 heads on the bigger bore motor.Position. MAST MOTORSPORTS FACTORY MAST 4.065" BORE LT HEADS - OE VALVE SIZE - CH-LTX-310512. $1,999.00. Add to Cart. MAST MOTORSPORTS FACTORY MAST 4.065" BORE LT HEADS - 2.165" VALVE SIZE - CH-LTX-310514. $2,499.00. Add to Cart. MAST BLACK LABEL 295CC LS3 CYLINDER HEADS - NO SPRINGS - CH-LSX-600238. WILL SHIP DIRECTLY FROM MANUFACTURER ...I have 862 heads on the 5.3 should I go with bigger intake valves for turbo application or will it make much of a difference? I have 862 heads on the 5.3 should I... - Glockner Oil RacingGet the best deals for 862 heads at eBay.com. We have a great online selection at the lowest prices with Fast & Free shipping on many items! Skip to main content. ... GM LS 706 806 862 241 799 862 243 CYLINDER HEAD REBUILD SERVICE 3 BUISNESS DAY. Opens in a new window or tab. Remanufactured. $459.99. Save up to 10% when you buy more. Buy It Now.I know 243's are good but didn't know if 862's are any good when they're right in front of me. They won't flow as good as 243 but you'll have better compression vs 243. You can have them ported for a reasonable price and have a good valve job done on them to make them perform. They'll never be rock stars but they'll do fine with that cam.GM 243, 799, & 317 LS2/LS6 Options: Performance Rebuild Package Our Performance Rebuild option includes our high end CNC'd valve jobs, precision valve grinding, milling to any chamber volume, cleaning, inspection, and professional assembly. Typical gains are 10-20rwhp. 226cc Full CNC Porting Package The go-to head for 450-500rwhp 5.7/6L's.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.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.The LS3 was run with a Holley HP management system and FAST injectors. With stock heads, the modified LS3 combination produced 552 hp at 6,400 rpm and 513 ft-lbs of torque at 5,000 rpm. After installation of the TFS Gen X 255 heads, the power numbers jumped to 571 hp at 6,500 rpm and 525 ft-lbs of torque at 5,200 rpm.For the price you pay for us to port 241s they will flow the same numbers as a stock 243 head." ... but I just noticed that Ai's 706/862 5.3 heads flow tremendously especially on the exhaust CFM (269CFM at .600). I just don't know how I could really benefit more from such a high exhaust CFM vs. having a higher intake CFM on TSP's 2.5 LS6 ...Page LS1GTO Forums, HIGH PERFORMANCE Best LS2 243 Cylinder Heads upgrade, DRP GM LS1 LS2 Cathedral Port 243 Heads are a high quality product for a best These 243. Home; Home › ls1 with 243 heads and cam hp › ... Build 862 Vs 317 Heads (compression)?? LS1TECH Camaro And, 43% OFF.302 heads on a 360 would lack upper rpm hp and basically become a cork. Too lil port volume/cross section. If they were full ported, then you may have something good . In stock form you are comparring the 360 that flow roughly 215cfm w/1.88 int and 165cc vs 302 heads that flow roughly 170cfm w/1.78 int with 124cc port volume.5.3 vs Vortec 350 in a Jeep; Changed direction on project. A1000 fuel regulator questions; Fuel boiling.... Breaking up at 5k and above RPM; ... 862 vs. 243 Heads; Holley Tunnel Ram; Easiest way to rig starter? perf rpm; 5.3 teardown/build; started my swap; Help with Rad Fans; FYI for Performer RPM users!!Our fellow tech writer and dyno-flogger Richard Holdener reports a gain of roughly 15 hp with stock 5.3-liter heads on a 6.0-liter. Our 5.7-liter head test bumped the average power by 9 hp but ...Friend of mine has a set of 243 casting heads that came off of a LS2/GTO engine. I have a stock 5.3 I'm working with, with the 862 casting heads, and... in this thread in this sub-forum in the entire siteforthman. 654 posts · Joined 2003. #2 · Mar 16, 2006. The old 69-70 351w heads have bigger valves and intake runner. Otherwise the 302 and 351w heads are the same. E7TE castings are albout as good as they get. The 289 heads do offer smaller combustion chambers but also smaller intake runners. I ran 302 E7TE's ported and milled so they had ...The 243 heads were also used on the Corvette LS6, but true LS6 heads had the light weight sodium filled valves. All these numbers we are throwing around are the casting number and they are stamped on the outside of the head. It's also the last 3 digits of the part number stamped under the valve cover.Chevy Cylinder Head LS1/LS6 243/799 - PAIR, Year:97-04. NEW CNC Ported LS1/LS6 Cylinder Heads .650 Springs 2.02/1.59 Valves PAIR. CNC Ported LS1/LS6 243/799 Cylinder Heads .650 Springs 2.02/1.59 Valves PAIR. Check out Our Other Articles: Everything You Need to Know about LS3 Heads. 823 Heads - Everything You Should Know About. All About 243 ...Get ready to feel the G-forces as we navigate the exhilarating terrain of power and performance. 862 LS Heads aren’t just components; they’re the driving force behind an automotive revolution, and the journey has only just begun! DIY Adventure: Installing 862 LS Heads Like a Pro. Time to get hands-on, gearheads!Showing the progress Porting the 862’s for my Turbo 4.8 project. Yes it’s a slow process and I limit how much I can do each day.I’m in the dirtiest portion ...The 2007 year had three 5.3L motors offered. The 2007 Classic (still a NBS) had the 5.3L with either the L59 (flexfuel version) or the LM7. The 862/706s are on the 99 and up 4.8/5.3L motors. The only difference about the L59 motor was the injectors. 2005 and up motors had the factory electric fans and electric TB.The 862 heads are inferior to the 706 heads in terms of compression, and they don't also flow well like the 243 heads because it doesn't have other competitive features; however, depending on your car's needs and budget, the 862 cylinder heads might be a good port for you.(Kitco News) - Kitco aficionados, it is now time to have your say in where you think gold prices are heading in the short-term.Read more on 'Kitco' Indices Commodities Currencies S...We find out which factory LS head works best under boost in this back-to-back test of the 706 heads vs. the 317 heads. 398ci LS, TKX, QP 9 inch, Strange pro iron case, strange 35 spline axles, Spc front upper control arms, UMI front lower control arms, Howe ball joints, upper +.5 tall, CPP C5/6 spindles, Ridetech coilovers, C5/6 brakes, C7 …The 862 heads are inferior to the 706 heads in terms of compression, and they don’t also flow well like the 243 heads because it doesn’t have other competitive features; however, depending on your car’s needs and …Jan 21, 2022 · RPO L99 and LS3 cylinder heads are aluminum with 68cc combustion chambers, rectangle intake ports with 257cc runners, D-port exhaust with 87cc runners, 2.165˝ intake valves and 1.590˝ exhaust valves. These heads can be CNC-ported to improve on flow and milled for higher compression. These heads are almost the same, but the L99 heads used a ...53 posts · Joined 2010. #4 · Nov 12, 2017. Unless you're spending money on AI ported 243's, go with the LS3's. LS3's flow more and will keep the port velocity up compared to the typical hogged to hell port jobs I've seen on factory cast heads. There are very few shops that port heads well, with AI being the best around.doing math an saying you have 2cc worth of valve notchs i got you around 12-1 comp wise with the 58.5 in for head cc an pistons out .006..with the 60cc 243s i got you at 11.8-1 with 2cc notchs,.006 out and .040 gaskets..hope this helps. I had them actually cc'd after I removed em.. 61.5.. Steve. 408, th400, 1100rwhp..The 5.3L was run once again in stock trim with a single S480 turbo. Run at a peak boost pressure of 9.6 psi, the turbocharged 5.3L produced 532 hp at 5,500 rpm and 555 lb-ft of torque at 4,700 rpm ...Swapping in 243 heads will increase flow a little, but unless you mill them first, you'll lose compression. If anything, you want to raise compression. For just a basic bolt-on 5.3, the 862 heads will do a decent job. ... The 706 and 862 castings aren't different, much like the 799 and 243 castings are identical. If you have 862s, I would ...GMC / CHEVY SUBURBAN 5.3 LITER V8 REBUILT CYLINDER HEAD. $225.00. Casting #. THIS IS FOR CASTING NUMBER 862 AND 706. WE ARE NEEDING THE CASTING NUMBER OFF YOUR CYLINDER HEAD. PLEASE FILL OUT THE FORM AT CHECKOUT OR GIVE US A CALL AT 800-942-4503 IF YOU HAVE ANY QUESTIONS. This listing is for a rebuilt GM 5.3 liter V-8 cylinder head.Another thing to consider is the life span of the MTI springs. The stock GM springs are guaranteed for three years, or 36,000 miles but generally last the life of the engine. Would you have this assurance with the MTI springed heads. Below are some GM numbers for 243 heads as a comparison. Stock CNC'd LS6 heads I E.100 .200 147 111GM's 5.3L LS1 head casting serves as the basis for this high compression / naturally aspirated oriented 3.900" bore specific offering. With your 5.3's, lightweight Manley Race Master Stainless valves, and lots of available P2V this is a great option for 440-480rwhp 3.900" bore builds. Our GM 5.3L CNC work will generate 11:1 compression on a ...GM 243, 799, & 317 LS2/LS6 Options: Performance Rebuild Package Our Performance Rebuild option includes our high end CNC'd valve jobs, precision valve grinding, milling to any chamber volume, cleaning, inspection, and professional assembly. Typical gains are 10-20rwhp. 226cc Full CNC Porting Package The go-to head for 450-500rwhp 5.7/6L's.It is an aluminum block 5.3 with either 706 or 862 heads, NON DOD. The 05-09 GMT360's got the LH6 and the 07+ will more than likely have 243/799's. In 07+ all the 5.3's started getting the 243/799 heads. The early years will obviously depend on what 5.3 equipped vehicle you have.The LQ9 is a 6.0L Gen. 3 small block engine used in GM trucks between 2002 and 2007. For marketing purposes, it was also known as the Vortec HO 6000 or VortecMAX. The information listed here is for the stock engine. Mechanically similar, General Motors' LS and LS-based Vortec engines wound up on almost every branch of the GM family tree ...The 243 heads as used on the LS2 motor flow at 260 CFM on the intake. LS6 243s (CNCed) with sodium filled valves flow a little better at 280 on the intake. The stock 241 head flows at 220 on the intake. Either head is a considerable improvement. You can not achieve these numbers by porting 241 heads.which heads should I get professionally hand ported 862 or 853. I was orginally thinking of porting the 862 which are 5.3 litre heads and then. enlarging the intake valves to 2". now I'm considering just haveing the 853s done any thought and feedback is appreciated. cam-LTs-FAST78-Susp.-Rims.You are going to make more power with 243's than 853's no matter what. Now it comes to cost vs. results. For the $600 or so for a stock 243 head, I probably wouldnt do it. In our experience, the best "budget" 243 heads are the Patriot Stage II LS6 heads. Those heads, with a LG G5x3 has been one of our most proven budget orientated power combo's.You could bore to the LS1 pistons run them and get a set of ported 243's. Add a Fast 90mm intake, cam, and you have an 400hp iron block LS6. Thats easily a 100K mile motor. For a stock 5.3L port the heads, cam, and a LS6/Fast intake and it might make 400hp on a engine dyno. But would make 300-325hp at the wheels.Fits. The price listed is for you sending your cathedral port cylinder heads (4.8/5.3, LS1, LS6, LS2, LQ4/9) to us for porting. Our stage 1 porting service will include the re-use of the stock vales. Stage 2.5 will include aftermarket 2.02/1.57 stainless steel valves. We also offer valve spring upgrades. PRC CNC Porting/Machining Service Includes:The reason is simple: The more you squeeze the air and fuel mixture in the combustion chamber, the more power you can create. In theory, forcing air and fuel in as small a combustion chamber as possible (measured in volume) will yield maximum engine compression and horsepower. There are a number of ways to accomplish the task.Re: 5.3 Chevy 862 valve job porting questions. by CGT » Fri Aug 30, 2013 1:43 pm. The 862's I have seen have the throat WELL over 90% with no material for a bottom cut. It will take a bigger valve to be able to get a decent valve job on that head, judging from the ones I've seen. SMITHBERGRACING. Guru. Posts: 1100.If you are just installing stock heads with no work, forget the 5.3 heads and just get a set of decent 243 heads which will still bump CR up 1/2 point on the LS1 (64cc combustion chambers compared to 66 CR of the 241 heads). 2004 torrid red with red interior A4 GTO (1 of 499)By Paul Johnson - March 9, 2016. This article applies to Chevrolet Camaro and Pontiac Firebird (1998-2002), as well as all LSx engines. The cylinder head (or "head") has …242 posts · Joined 2007. #10 · Jul 10, 2009. Sleeper S10 said: The 5.3 L33 comes with LS6 Heads: L33 Vortec 5.3 325 Gen 3 Aluminun Engine Vin "B". 310 HP/ 5300 HO. LS6 Heads, Casting #799 (Originally developed for the ZO6) 9.9:1 Compression. Flat topped teflon coated pistons with floating wrist pins.Feb 18, 2024 · 706 heads tend to be more popular than 243 heads with those who run naturally aspirated engines. While they don’t have the same size combustion chamber they also don’t have the tendency to lower the compression ratio and reduce horsepower. When looking to replace your heads, they offer a high degree of consistency since they are ...The other option, assuming one or both heads are having actual issues, is to hit a local junkyard and pull another set of 862's for <$100, clean them up, and slap them on. 2004 Silverado 1500 (ish); 2005 Silverado 1500. 1964 C60; 1985 K30 Detroit Diesel.Product Details. Lingenfelter offers a CNC ported version of the 243 casting aluminum cylinder head used on the 2001 - 2004 Corvette ZO6, Cadillac CTS-V and the 2005-2007 LS2 powered C6 Corvette, 2005-2006 GTO & SSR. The port and chambers are carefully designed to provide the best combination of high flow capabilities and improved port velocity.The 4.8L engine is also known as the Vortec 4800. The engine specs and information here is for a stock LR4 engine. These engines are strong and durable. Many people use them with boost or nitrous. With upgraded internals, the blocks can handle over 1,000 hp. Mechanically similar, General Motors' LS and LS-based Vortec engines wound up on .... Sort by: Add a Comment. J8ke_Stampede. • 1 yrWe find out which factory LS head works 87LC2. This is rarely brought up, but the combustion chamber design of the L92/Ls3 heads is superior to the 241/243 chambers. The cathedral heads use a "heart" shaped chamber where the square port heads use a "butterfly" shape. The butterfly design is said to improve tumble, swirl, flow, flame propagation, everything. It still used 799/243 heads but also utilized vari The 243 Heads are cast iron cylinder heads that have been CNC-machined to create larger intake and exhaust ports. The combustion chambers have also been machined to be smaller, which increases the compression ratio. While the 243 heads are not the newest or best option out there, they offer a great value for the price.2005 GTO QSM, 418" NaturallyAspirated ,Bullet Racing cam, 243 heads, 6speed, Kooks 1-3/4" headers w/cats ,matchported FAST 102,NW 102mm, 3.73 gears PB in 1/8th 7.76@97 on Firestones with 1.97 60'. Tick Performance tuned. 862 s Vs 243 s..... So what the differen...
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