Chamber softening

So ive been reading into softening chambers for boost. Has anyone had sucess with edelbrock performer heads. I know i cant take too much because of thin spots into water. they already have bowl and some port work. Seaing about opening it up to a felpro standard gasket, smoothing out and opening up what i can should help flow and lower compression a it as well as slow flame front to open tunning windows.

i have done this to a set of C460 heads with a pro-charger...and a nos powered 351c cleveland...
seems to work pretty good on the 351 it can run a little more timing without detonating we are putting 400hp of nos into it...the C heads i will let you know in a couple of weeks when i get it back into the car and run it again..