I have a 498 stroker motor with stock iron heads, when done are modded for pump gas and shop "tweaked" them for better performance. (have no idea of their definition of "tweak"

What horsepower increase could I expect by getting the edelbrock performer heads or others?? 440 source has a complete set for 899...what HP would I expect...Thanks to all in advance...Happy New Year...Thanks MOPARTS

Depending on the CR and cam selection, Neither of those heads will show their true potential untill they are ported.

Depending on the level of "tweak" on your iron heads they could be close to an OOTB eddy.

It would help to know the particulars of the motor.

Might also be a good idea to think about some of the other heads that would work well with less work but still leave you the room to grow if you desire.

You would be better off to spend your money on a set of 440 source heads. To fix a set of old cast heads properly you're looking at spending $1000.00 any way. Unported you should still get 500 horsepower. I have a friend that has a 493 with with lightly ported 440 source heads and is getting 600 horses out of it. For street use I would also recommend a lunatti voodoo cam. I have used them in my engines and loved em!!!

9.5 to one pistons
comp cam..gross valve lift...525
tappett lift..275/287
duration...231/237
hydrallic cam
60 over bore on 440
harland sharp rockers