What sort of power are a set of C3AE-C heads capable of? These are the 390 heads, 72cc chambers. I'd look at upgrading the valves to 2.09"/1.65", a good valve job, bowl blend, smooth the valve guide bosses and a general port clean up. Any idea what they should be able to flow?
I'd be looking at running them on a 390, around 10 to 1 comp, solid cam(maybe a Comp 270S or a 282S), tripower intake, long cast headers, 4 speed and 3.5 gears in a Galaxie.