318 build up
I'd look into the KB pistons that deliever a zero deck on the 318. I think the number is KB399. KB.com should help there.
The rest of the build.... what is the intended gear ratio/tire size?
What RPM band do you want to operate in? (2,000 - 6,000 for example)
How much stall do you want to use or is to much.
How fast is it you want to go?
Once I understand this, I can zero in better on a cam and combo to run with.
What intake do you have now?