I used to have that setup and loved it! I had the e-cam tho with 1.7 rollers. The gt40x heads are a really good upgrade to a 5.0. I took mine to the track and ran a 13.0 like 5 times consistant. Mine is 5speed tho i dunno if u are or auto. I also had a little bit more stuff than what u said, which u can see in my sig. I obviously didnt have the turbos back then or a few other things. But yea the difference with a good H/C/I combo is pretty amazing. It really brings out the fun in the car. Plus if you have a good rear, u can powerbrake it with a stick car and do burnouts in 3rd gear! =)
you are probably looking at about 275 hp and like 325 tq