yea i know another ls6 head question. but can anyone figure out what kind of compression ratio i would be at? ls6...(yes real ls6 heads) milled to 59cc/ or roughly .025, on stock head gaskets, on a lq4 6.0...if not give me a link were i can figure this out. i will be running premium gas anyway, just curious how much compression it would be.......thanks nick

 

Well, Stock 5.3 heads are 61CC and they net about ~11:1 CR when added to a LQ4. So, you will be above that.

Google CR calculator if you need it closer than that. You'll need to measure how far the pistons come above the deck though...

 

thanks dude i thought i should be fine at .025 because i herd somewere that the max you wanna mill is about .040. i thought my pvt clearence should be fine at .025. plus the lq4 has dished pistons.

 

i would call trevor at texas speed he is always a great help with that kind of stuff...

 

An ls6 head has 64cc combustion chambers, right? If so, then i dont think a .025 mill job will get you down to 59cc's. Mabe 61cc's? That would get you to about 10.8 to 11 compression.

 

ahh ur right 59cc is .035 milled...thats my bad....just did a search and found a thread..59cc milled 243s with stock head gaskets will be at 10.7:1 to 10.8:1 CR..

 

Assuming your pistons are about .007" out of the hole (just an average, but it doesn't change this a ton if it's a few thou off from that), 59cc chambers, and GM MLS gaskets you'd be at about 10.9:1 static.

 

the heads are already milled to 59cc...just need to see were i am at./suggestions?

 

ill take your word for that quote sir

 

Got your Pm,that is correct!!