oh a converter too? that makes more sense... ya you're pretty much right in line. You race at a little higher elevation or hotter weather generally?

 

nope stock converter sslow

 

If its out of an Envoy I believe its a LM4; which is just an aluminum 5.3. There's no other differences between it and a regular 5.3 other than block material. To bore it to LS1 spec you might have to get it sleeved which cost an arm, half a leg, and a kneecap.

Although if it does have 799 heads then maybe it is an L33? Check to see if the pistons are dished or flat tops.

 

If it is the all aluminum with 799 (243) then it is high output one.. i believe it is 9.9:1 unlike the regular 5.3. Nice score

 

I don't think there's enough meat in the cyl walls on the alum 5.3l to make it a 5.7l......

 

what happened with the 6.0??

 

i havent tore it down yet, but it is aluminum with 799 heads, i sure hope it can be brought out enough to a 5.7

 

it was busted, right under the number 1 cylinder

 

I thought the all aluminum envoy/TBlazer 5.3's came with the older 5.7 ZO6 heads?