I may have found an LS1 shortblock I can drop in my truck but I want to know if I can use the 862 heads from my 4.8 on the LS1. Also, what will the CR be if I use the 862's on the LS1. Thanks in advance
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I may have found an LS1 shortblock I can drop in my truck but I want to know if I can use the 862 heads from my 4.8 on the LS1. Also, what will the CR be if I use the 862's on the LS1. Thanks in advance
It will bump your CR up a hair, 4.8/5.3 heads and LS1 heads flow the same, the only difference is the combustion chamber.
So about what is my CR with 862's on a 4.8L and what will my CR be with 862's on an LS1 ?
it's a pretty common mod with ls1 guys to raise compression. I'm not sure the exact numbers, but you may want to lower the boost a psi or 2.
Looks like 66cc combustion chamber volume. Should put ya around 10.5:1 I think.
Not the best choice for a boosted application I wouldnt think. Too much static compression. I would think you would be better off with some heads off of a 6.0 umm 317s i think, they are supposed to slow as well as 243 heads and are cheaper? You could probably sell your 862s and break even. You will have a hell of a time avoiding pre ignition with pump gas with those heads and any kind of boost at all.
Ok there are 3 sets of 317s on performance trucks classifieds right now. One set is less then $200! If your gonna run boost go get em!
+1 truck heads would boost your compression too muchQuote:
Originally Posted by aj06bolt12r
http://ls1tech.com/forums/ls1-domest.../t-111207.html
the truck heads are 63 cc and the 317 heads are 72cc
Unless you slapped some dished forged pistons in it. That way you gain some strength and you can keep your heads.
So an LS1 with 317's would put my CR around 10:1 ? If so, then I think that would be optimum for about 12 psi of boost.