JT86SS

Hey guys, i have a 5.3 im getting ready to wrap up. the engine had a set of 706 castech heads on it, from what i hear they have a bad reputation for cracking so im hesitant to put them back on. i have two sets of 317s laying around. although i have read many times dont waste money milling the 317s for boost, im wondering has anyone actually tried it. and how much material was shaved with no issues. i im trying to retain some bottum end torque out of boost. i dont plan on running more than 15lbs.

Thanks JT.

Blown06

iTrader: (32)

I ran the 706's for 4 years and never any trouble. Aside from that, I wouldn't mill the 317's too much. You need as much deck thickness as you can get. Maybe .030" at the most???? Your power is gonna be made with boost....so don't get too caught up in compression if your using stock stuff.

What compression ratio do you get with unmilled 317's on a 5.3?

JT86SS

Yea its going to be stock other than cam & head studs. From what i have read C/R around 8.2-8.5 with the 317s. Theres roughly a 10cc difference in the combustion chamber volume. I have ran them before on my first 5.3, it wasnt horribly bad. But after switching to the 862 there was a noticeable difference (in the bottom end). That was in a gbody with 3.73's.

Thanks

Wicked69

Why not just use the 799 or 862 heads? They will work fine on the 5.3 and boost. If u want more compression throw some pistons from a 4.8 in there.

JT86SS

I dont have a set of those heads. I wanted to see if anyone had experience with shaved 317s And boost before i decided on my next move. Im jist trying to make an effort to use what i have. I may have to try it and share my results.

Wicked69

I missed that. Yeah, I got you. That was how I used the 862's on my 6.0. Ran like a raped ape even out of boost at 11.1!

JT86SS

I bet that was fun to drive.

Blown06

iTrader: (32)

Use the 706's.

kainedogg

iTrader: (23)

On E85 though right?