1986 firebird upgrades?

[Stabbibble]

I wanted to pump up the performance (and gas mileage) of my 1986 firebird and i was wondering because some people told me not to get high compression pistons or hyper eutectic pistons cit would lead to problems with the rest of the car. So what all would you recommend doing to it and where might i be able to attain such parts

 

[melsg5]

Speak to whoever is going to do the engine rebuild, it doesnt sound like you intend to do this yourself.