pistons, heads, both?

Use a new set of rhs heads.
They have a closed chamber design to boost your compression and will handle the cam that's in your engine as far as the valve springs go.
You could bowl port them and go to a 2.02 valve if you wanted to.
They come stock with a 1.94 /1.60 set of valves.

Sounds like you want to go faster???
Raising your compression is a great idea but so is making the hole cars drive line work together.

What converter and gear do you have in it????