i'm lookin to do alittle home port to these heads. smooth them out and what not. can you get much out of doing these heads. what would be best to do, gasket match and some bowl porting for some et and mph pickup? anyone done these? thanks for the help!!

What is the current engine/tranmission/gear combination?

I've seen 283 cfm @ .575" out of a set of cast iron small block heads. +.100 small chevy valves (smaller stem for more flow and lighter weight) 2.200/1.600. Takes a bit of work and a 3/8" double cut burr, 6" long seems to work best. At least it did for me. Once things are opened up a 1/2" burr will fit, but if you start with it you'll end up getting a bunch of bouncing around, and if you're like me, it'll pi$$ you off. I'm referring to the areas to either side of the guide looking down the intake port from the intake flange.

I think it's worth making chips...

Many machinists would prefer working on a set of 587 or 596 heads than a set of 915's do to the fact that there is more meat to work with and they can do more with them.

That thing doesn't run bad for the converter, gear and tire combination.
E-85 throws me but, it must share some of methanol's torque building
characteristics??

Porting the heads will definitely pick it up. What valves?

I use this 7/16" oval double-cut on a 4" shank for 90% of
all the head porting I do. It's just about perfect for me.

Brian, give me a call. 574-340-1966