The Edelbrock heads have far superior flow than any of the cast heads. -Also better than the best iron castings (ram air IV).

-The weight factor is also a good point, and with the better flow, you'll be able to use a slightly bigger cam (gain as much as 70TQ+/70HP+) -or just use your old cam, and gain loads of torque, and about 30-40 HP.

If you slap on a pair of headers, expect as much as around 100HP+ extra.


http://www.carcraft.com/techarticles/116_0101_501hp_455_pontiac/index.html

Then (as 69firebirdman points out) you might destroy your rearend/transmission.

So be sure you have the right parts..
But I would warmly recommend those heads. (Performer RPM)