Doctor Geek

Yeah, the PI heads and blower will make more power than just the blower alone, but that’s not what you stated in your original post. You only ask which of the two would make more power….the blower, or the heads. And in any case, the blower on you stock NPI heads will make more power than just a PI swap alone….hands down. Now if you want to go with the PI heads and the blower both, you could do that as well, but you’re considerably adding to the cost, when you’d be just as well off to port the stock NPI heads. It may make more power, but not as much as you’d think. Remember, PI heads on a NPI motor up the compression considerably. Doing this requires the need to add fuel and pull timing in order to safely run any useable boost levels. So although the PI heads have the capability to flow more air as a whole, boost levels will have to be kept lower and tuning will have to be very conservative to keep from damaging the set up. I'm not saying that the PI swap is a bad idea, but an unnecessary expense IMO. It’s cheaper to port the NPI’s and buy a set of used PI cams than it is to do the headswap.