my question is, would it hurt or help me if i install a set of 5.7 heads on my truck. i have a set laying in my shop and was going to build a 5.7 and install it but the block i bought aint any good. i was thinking of having them shaved so i could have about 11.1 comp and install a tr224 cam. or would i be better off finding another block and building a 5.7 or 6.0

 

if i were you i would find another block... i think i asked this question almost a year ago and they said the best thing to do it port and polish my heads for the 4.8L and going bigger could hurt... but i beleive i was asking about 6.0 heads on a 4.8 tho.

 

ok, i know i heard people talking about the heads lowering your compression and hurting bottom end and all but i figured you could shave the heads to cure to compression and if i lost a little bottom end it would be ok cause i have a hard time hooking up now.

 

yea, im not good with compression ratios and what not... never really understood any of it or tried to, you'll have a definate answer soon im sure, good luck with it.

 

The stock chamber on those heads (assuming they are LS1 heads) is 67cc. Your heads stock have 61cc chambers. It is going to take quite a bit of milling (like .040-.050) of the LS1 heads just to get you back to a stock CR. Forget about 11:1 just by milling heads. Not to mention the 2.00 intake valves will be shrouded against the small 4.8 bore, especially with the milling.

LS1 heads do not flow any better than stock 5.3/4.8 heads, so like was said before, you would be better suited doing a minor port and polish and valve job on your stock heads.

 

It would drop your compression to 8.8:1 and milling to get it back up would require a set of shorter pushrods most likely. Just another thing to be a pain in the ****. Porting a set of 4.8/5.3 heads or building a 5.7 out of a 5.3 crank and your block would be the best if you want to utilize 5.7 heads.

 

ok thanks for all the replies. im going to look for another block