boring my 318
The 302s were freshly rebuilt with some light port work, bowls and gasket match done professionally. The intake was an Edelbrock Performer RPM. The J heads were home ported (my first time porting heads). The performance drop in the high RPM range was calculated via the seat of the pants-O-meter, same with the low end toque increase. The only real power comparison I have is from running my car at the track.
Getting the gasket match on the 302s to work with the RPM intake took a bit of work; however, the skinny intake port pinch was still present
I literally could not fit my index finger in the intake port past the first knuckle.
I believe the cam and intake combo was better suited for the 360 heads, but I doubt that a smaller cam and intake with the 302 heads would have made more power
just my opinion.