Speedmaster Small block porting tips and results Part 1

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.