Hey guys just wondering if i could get some help with my CR. I'm rebuilding my 350 and just wanted some opinions on what CR to run. The block(72' 010) will be bored 0.30 will stay at the stock deck height which i think is .020. i'll be using stock crank with lunati 5.7 rods. Have stock(for now) 64cc 062 vortec heads. Haven't got pistons yet. The cam is a Voodoo with 233/241 @ .050, .504/.525 lift with a double roller timing chain. I've heard a couple of different things, mostly saying go under 10:1, but that seems a little low for my setup. Any and all opinions are welcome. thanks!
Joel

 

Will you still have a knock sensor?

With iron heads and pump gas, you'd best keep it no more than 10:1.

 

No there isn't a knock sensor.
Any ideas for pistons then? I've been having trouble finding pistons that keep my CR below 10:1 but also have a floating pin for my rods.

 

Floating pins? You're looking at higher end pistons now.
Your basic 5cc flat tops with normal deck height and shim gaskets should put you exactly at 10:1.
That's a good engine combo, very popular. Lunati 60104 and vortecs is a winner.

 

You should also consider having a proper quench distance in addition to your compression ratio. Select a set of pistons that will give you a good quench. I motor with a 10:1 CR and perfect quench of around 0.040" will be less likely to ping than an engine with a 9.5:1CR and quench distance of 0.050" or higher. Consider some of the KB hypereutectic pistons. They are a bit more expensive but well worth it. They have some dished pistons that would put you in the 9.5 to 10 CR range, but will also give you a good quench.

 

I looked at some KB FT hyper pistons, I think that seems like a good choice. Thanks for the help guys!

 

i think the kb120s offer a floating wrist pin and will keep your cr low enough with 7cc reliefs... i think like 9.6-9.9:1 with a .015 headgasket or with a zero deck and a .041 head gasket