Lucidus

I just need a few things cleared up.

First question-3.25" stroke and a .030" bore will bring me to 331, correct?

Question 2-What is the difference between flat-top and dish pistons?

promustanperformance

That's correct. Flat-top pistons, as you might imagine, are flat on the top. Dish pistons are sort of like a bowl on the top. They're designed to centralize the fuel in the middle of the cylinder. If you need any performance parts, let me know. Hope to hear from you soon.

Lucidus

What are the benifits of both types of pistons?

promustanperformance

Dish pistons are more commonly used with blower applications. For most applications, a simple flat-top piston with notches for valve reliefs will do. They also have dome-top pistons. I will not pretend, I'm not an engine builder and I recommend you speak to a professional if you have a unique situation or plan on making an exotic combination. However, like I said, most combinations can utilize a piston with valve reliefs for large valves.

tinman

If you want to keep things simple for a street-strip type car, use the flat-top piston. If making a stroker (331,347 etc), just be sure of the head chamber size in C.C. so you don't end up with a whole bunch of compression. You don't need huge compression to make good power.
I'm referring to carbed/N.A. engine.
The 'pop-up' types are for more of a 'hard-core' type use. There is even some arguement here if they are truly benefical. IMHO, they are not, usually.
I would not use the 'dish-type' unless you know you are going to have too much compression.
BTW, which heads are you using??