May 11, 2021 · The XAA suffix 454 LS6 crate engines had 10.2:1 compression, I believe they had a .340 tall or -30 cc dome. My 1970 SS454 LS6 SuperCar certified stock appearing 11.90@113 MPH My 1964 Big Block Corvette Gasser

Dec 8, 2006 · An LS6 on F70 X 14 tires would helpless, with slicks probably well into the 12s. We had our COPO Chevelle about a month before putting bigger tires on it. Made lots of smoke going no where. The LS6 probably made 35-40 more hp and would be even worse. To build an LS6 engine will cost a LOT of money compared to the changes listed above.

Dec 5, 2005 · In 1971 the LS6 was factory installed in the Corvette ONLY and was equiped with alum. heads. These heads were open chamber and Chevy didn't make a piston change, so the compression was down in the 9's. One other little drivel: When you see an LS6 type intake with a cyl number on top of each intake runner it's from a '71 model LS6 Corvette.

May 3, 2007 · My Chevy Power / GM Performance manuals all list the LS6 cam (#3904362) as 307I/298E at lash point, 275/271 at .010 tappet lift, and 242/242 at .050. John Save Share

Dec 22, 2013 · "The term LS-6 is one of the more "bastardized" logos in Chevy folklore. Just what is a "LS-6." A LS6 is: a 512 4 bolt block, Steel tuftrided cross drilled fordged steel crank, fordged TRW 11.1 closed chamber pistons, 291 closed chamber rectangle port heads, 2.190/1.720 valves, 520 lift 242 @ .050 solid lifter cam, 3/8 pushrods, H stamped steel rocker arms, dual plane aluminum intake, special ...

Mar 19, 2025 · Selling your 1970 Chevelle SS 454 LS6—a Cranberry Red, black-striped survivor with 29,348 miles, loaded with ZQ9, G80, GW8 4.10:1 axle, ZL2 Cowl Induction, U14 gauges, Z15 SS 454 package, M40 TH400, numbers-matching "T0117CRR" engine on a "3963512" casting, single-owner history, and build sheet—is a big move.

Jun 7, 2005 · They have 11 to 1 CR, forged pistons and big strong 7/16" bolt rod forged rotating assembly, big valve rect port heads, and a hy-po for the time solid lifter cam whereas the lesser motors generally had 10.25 to 1 CR., mild to down-right small hy-cams, cast pistons, a cast crank and smaller 3/8" bolt rods along with oval port heads and the small valves..

Apr 12, 2005 · "The LS6 heads that came in the LS6 Chevelles were CLOSED CHAMBERED no ifs, ands, or buts about it".....Actually they were "semi opened" or "semi closed " if you prefer.They are Bigger CC than the 840s that preceeded them,but less than the full open chambered style.The 188 is an open chamber used on later crate ls6s,thats why people call them ...

Nov 27, 1998 · The heads say HI PERF and the Numbers as follows 3994026 and yes they are open chamber and rectangular port cast iron and yes they made an LS6 in 1971 for an extra 3000.00 dollars or so if you really wanted them. I know this because when I ordered my 1971 SS ElCamino 454 that was my choice when it came to either the LS5 454 or the special order ...

Oct 10, 2010 · 188 Corvettes where built in 1971 with the LS6 motor. No LS6 option for Chevelles after 1970 They had open chamber aluminum heads and a .095 tall domed piston. The crate LS6 motors still had the original 1970 .270 tall dome but had open chamber cast iron heads,which gave the motor 10.25 to 1 vs. 11.25 to 1 in 1970 with 107 cc closed chamber heads.