I have been away from this to long. I have a 350 chevy that is bored out 30 over. I have installed the new Ohio pistons that are some what a flat top but with a small rise with the section milled out for clearance for the valves. Now with the new world heads SB chevy S/R torquer installed, I can not go to anything hotter than the R45 plugs. Anything longer would push the electrodes down. So, I know they are close. I just need to figure out, how do you calculate the compression ratio that the motor has? The camaro runs great and seems to have a lot of power. I just need to know what the compression ratio is so that I can go back and see what cam is best for this. At the moment I have a 327-350 horse vet cam in it. Not sure if I can do better. I just want to get the most out of the motor. thanks  

Do you know what size dome is on the piston tops also what size cumbustion chamber do the heads have.  

There a lot of factors into finding out the exact compression ratio is.... The size of the combustion chamber, piston shape and size, shape of valves, head gasket thickness, connecting rod length, and finally if the piston goes beyond the top of the deck at tdc. Look on summitracing.com I am pretty sure you can find a better cam to fit with the engine. Find  cam with a big lobe separation for more vacuum and a meaner sound. You don't need a mechanical roller cam because it is not so much a race car, a healthy hydraulic roller will do you just fine. Just make sure you buy a matching hydraulic roller lifter set to match.  

Thanks,I have to juggle my thoughts on everything. I built the motor back in 2002. The piston dome is not all that big but big enough that the dom had to have a recess to clear the valves. The rods are close to stock rods. I used the stock size fel pro gasket. I think when I got the piston to the top dead center my depth guage showed about 50 thousands from the top of the block to the top of the dome. I do know that there is not all that much clearance as the next step hotter plug beyond the R45 would not work as the electrode would not clear causing the electrod to push shutt. So I have to stay with the R45 plug. The heads are 76cc heads with 2.02 /1.60 valves.  thanks  

What's the compression of the pistons, as listed by the company that made them?  

Thanks, I will have to go back and do some research on the ohio pistons. I built the car back in 2002 and it has been setting since I am across the pond, I went back to check with all the data I had saved in the glove box but things have been mis-placed. I have the car in storage as it runs good. I just want to find what i can so that i can re-do the cam when i go home on leave in August. let me try to check with the Napa on-line and see if i can find the pistons. thanks  

I tried to go back and find the info on the pistons. Can't find it in my pc that I have here. I had a cam in the motor that I took out because of some problems but think i gave up to soon. I have a cam with 480 lift 292 duration  cam lift 320 lobe center Intake 197 exhaust 111. Is this to much of a cam? Im running world heads s/b chevy torquer with 2.02  160 valves. bored 30 over. I had to install a 3000 stall converter to get it out of the garage. Now I am thinking that the springs on the torquer heads may of not been right. Any idea on those? I just could not get much power. My boy wants to go to something more than the 327/350 vet cam. Just checking to see if the other cam would work and any ideas of what i could of not done right. If not, any idea of what kind of cam with specs would be a good cam to run. He kind of likes the radical sound, thanks