Head question 317 vs. 706 on a lq4 (daily driver)
 

My question is...i have a 2005 lq4 in my crew cab
I want more compression on my crew cab and I have a extra set of 317 and 706 heads...
Should I mill the 317 heads as much as possible and how much is possible?
Or
Have a set of 317 valves in the 706 heads and keep rest stock?

I know the 317 heads flow better but this is not a race truck...it is a crew cab on 26" wheels... I would like more pulling power and hope to gain alittle more fuel economy
With tge bigger valves in the 706 it should help on the flow some as well correct?
I would like 10.5:1 - 11:1 cr

If you want the flow of 317's with a tighter chamber, trade the 317s to someone with 243s (ls2/ ls6 vette) who wants to go FI. This won't get you to those CRs from 9.4:1 though, I don't think. Do you know the dish of the LQ4 pistons? I used to... Doh!

I can't help on the 706s -- don't know anything about them.

Grab some flat tops / LQ9 slugs. That gets you to 10.1:1 with 317s, then mill the 317s as much as you can (or grab some 243s).

Its not worth the trouble, i milled my 317's .030 and didnt gain any... i rather have more flow than bumping up CR.

Debating the same thing here. I have a set of 317's and a friend wants to trade me for a 706's because he's going boosted. Going to port the 706's if I decide to go with them.

Not even worth the swap to the 706's. Nothing about them is better.. If you want comp, go 243's or just have the 317's milled. Them and the 243 are one of the best flowing stock heads there is...