have an 87 tpi outta of an iroc in my 89 rs. previous owner had it bored over to make it a 355 along with a crane cam lifters/rockers. everything is still stock as far as the heads and intake go. I had it put on the dyno and just barely got over 200hp before it started missing and back firing etc. Did a complete tune up of accel wires, coil, cap, and some delco plugs. Waiting to return back to the dyno soon. Was given the suggestion to swap the heads over to the vette heads L98 i believe to get more out of her. Would this be an extreme difference in power? was wondering what other mods some of you guys have done to your 3rd gens w/o breaking the bank of course lol. Have also been tryin to do alil research here about the switchin out the runners and portin the plemun. The previous owner couldnt remember the size of the cam incase anyone is wondering. This isnt my d/d either mainly for play on the weekends. Appreciate the input fellas thx