[Rev]

I don't think that's too bad for your set up. Seems like the engine has been rebuilt at some time. (306, forged pistons, Sealed Power, E cam, etc.). Hows the cranking compression? And how many miles on the rebuild?

A windage tray and crank scraper can add a couple of ponies without any negative effects. Some kind of cold air / ram air system also can help some without hurting anything. As you mentioned, better heads are needed. I like TFTW or AFR.

The March under drive pulleys didn't hurt my cooling any on my car and it was always borderline. Now with an Edelbrock water pump, 4 row radiator, and a Shelby front valance, and an auxillary 16" electric pusher fan on my '66, it stays around 200 F even on hot 100 F days, even with the pulleys. I was worried about cooling and charging before I installed them, but it turned out to not be a problem for me.

Rev