Engine performance modifcations?

Ok, heres the deal, Next summer, my father and I are going to rebuild my engine, and I want to put performance parts back on after it's all taken apart and everything is cleaned. The problem is, I dont know of any peformance parts to get. I know right now of cam shaft, and port and polish, but other than that, my mind is empty. I have a 1989 Oldsmobile Delta Eighty Eight Coupe H-Body(not too many of those) with the FE3 Suspension(gran touring), and the series I 3800 V6, which comes stock with 165 HP. Im going to order a Flowmaster muffler 40 series next week, and pick up a K&N Filter, for minor mods, anything that can be added internally would be appreciated to know about.

ok summit racing has pistons that are .030 over bored, GM FWD performance has I believe a full race cam for it...:comprage1

correction: laser cams has some
http://www.lazercams.com/Buick6EvenFire78_92App.html