Direct Connection ( Mullen LA ) heads

If Mullen was flowing at 3 inches of water column (I thought it was 10 but I think wrong a lot) the conversion to 28 inches is pretty useless like GE a mentioned above.

The air column at 3 inches behaves completely different than what it does at 28 inches. O any mathematical formula will be at best a close approximation.

If a port looks god at 3 inches it may suck at 10, look better at 24, go straight to hell at 28 inches and raising the test pressure higher is a crap shoot.

I tested everything at multiple pressures, to the point of testing the same lift at 4 or 5 different pressures.

You start to see trends that develop, and usually the trends will tell you to do things that are contrary to conventional wisdom.