Which head is better 915 or 906?

[LovetheA's]

This is one for the guru's. Could someone please explain this to me. I know that in 1967 the hi-po head that was common on the 383 or 440 was the 915. I also have been told that because of it's closed chamber design it will easily raise the compression resulting in substantial power gains. What I need schooling on is a comparision. Assuming you have two identical motors say a 383 or 440 from carb to pan expect for the heads. One motor has a set of 915's on it and the other a set of 906's. If the compression ratio on both motors are identical at about 10 to 1. Which motor makes more power, torque and flows better and if so why? Was always curious about this?

Carl

 

[oldkimmer]

......915 was a 67 440 head only........If the 915 motor is a quench motor it will make more hp and torq because of the quench if it doesnt end up with detination.....even the open chamber at 10.0 to 1 could ping.....u will need good gas........a 9.0 to 9.5 would be a better choice..kim.........

 

[IQ52]

Neither head has an advantage over the other as a 10:1 915 head and a 10:1 906 head will require a differently designed engine to accomplish the same compression ratio. Plus both heads have essentially the same flow potential. You must be smarter than the cylinder heads you are working with.