I recently bought a 99 firebird with an ls1. It Wouldnt crank so I pulled the heads off. 4 of the pistons were busted and had dropped down into the oil pan. There is a crack inside the cylinder walls but i believe it just cracked the sleeves. Either way i bought a completley disassembled 98 ls1 off craigslist and now im slowly rebuilding it. I want to make as much horsepower I can. What is the best route to go to get as much horsepower as i can while my motor is disassembled.

 

Good set of heads/cam would get you 400+whp. Depends how much your wanting to make.