Speedmaster Small block porting tips and results Part 1

rumblefish360 said
I honestly think that the OOTB head isn’t a bad deal and flows just fine for the price. It shows an easy 47 cfm gain on an average 360 head. The best I have seen reported from a 340 X head was 220 cfm at peak. That gives these heads a 27 cfm advantage.

With my basic layman’s math above, this loosely translates into a 54 hp gain over a stock head IF your looking to take advantage of the heads flow abilities.
If you went a little nutty on compression and cam and etc.... you know the drill and direction I’m going in, I would not be surprised to find a 70 hp gain on the race oriented engine.

Rumble your spot on! My personal experience using these heads over the last 4 years would be right in line with your statement. I ran X heads for 30 years with some Port work and very nice valves, :/- Speedmaster heads where a noticeable power advantage. But to
Buy a part take time, sweat, blood to modify it make it better is what hot rodding is all about sure there are better heads out there for more money but taking a lower-cost piece and building it to be equal or even surpass a so-called Superior piece well that's just awesome!