Hey Guys,

I need one of the experts here to help me out. I have a 5.3L that we just swapped in a z06 cam and 243 heads w/ the sodium filled valves. Can you tell me the CR drop i'm going to get from going from the 862 to the 243 head as well as expected gains from the head/cam swap? Bottom end is stock minus we put in arp rod bolts.

Thanks,

Chris

 

I'm no expert, but in the S-A Design book "How to Build High Performance LS1/LS6 V-8s" it said LS6 heads had a 64-cc chamber and the LW4 had a 61-cc chamber, and that it made less power because of a loss of compression. Didn't do it, haven't seen, just read it, and not an expert. I read that book, and two more, bought the LS-6 cam and springs, then found this forum, and wish I would have done a bunch of things different. Search the forum for 5.3 builds.

 

im no expert either, but i bet those heads are counter productive to what you are trying to achieve, especially with the minimal gains that cam will give you in a n/a application. get those heads milled down and it will help a bunch

 

Well, the truck isn't a NA application, it's going to have a 76MMm split t6 housing bolted to it.

 

well that explains a lot

disregard my post then

 

Can someone tell me how much the Z06 heads will have to be decked to achieve a 11:1 c/r ratio on the 5.3L.

E85 FTW

 

y so high on compression if u had mentioned it wasnt going to be n/a.

 

Probably something like .070" with a .030" head gasket. In other words, not gonna happen.