I did a before and after dyno pull on my car a couple months back. With the stock long block (stock motor heads and cam), 73mm maf, 65mm tb, underdrive pullies, 1 5/8 primary bbk unequal shorties, 2 1/2" Bassani o/r x pipe, 2 1/2" dynomax catback and a few other assorted bolt ons I dynoed at 210 rwhp and 270lbs of Tq. After i put box stock Edelbrock 6032's, TFS stage 1 cam, ported Cobra intake 76mm maf, 70mm tb, 24# injectors, 190lph fuel pump and a BM elec. fan I dynoed at 283 rwhp and 315lbs of Tq. I ran a best of 13.9 @ 96 mph on the old setup and I've been told i should be abe to hit the high 12's with good driving with the new setup. I'll be dynoing again in a few weeks to see how much help bumping the timing, fuel pressure and some long tubes will help me but I'm told that 300rwhp should be easy with that.
The heads are the biggest and best mods you can make on your motor, but they need alot of support too. You'll need a bigger tb, fuel injectors, fuel pump, adjustable fuel pressure regulator, and you will definitely need some subframe connectors so you don't warp your car when you launch.
