AFR Heads

I took edelbrocks off my car that had been ported by a local guy, then gone over and ported more by a shop that has won enginemasters type competitions and is a well known Mopar shop. The shop that did the small block Victor heads on the 376 cube 360 that’s been posted on here numerous times.
I took them off, swapped to bloomers and new headers and picked up half a second and better than 8 mph. Same cam, convertor, carb, gears , etc, etc.
Fair enough but don't seem too relevant to a thread about the AFR heads which seem to be on par/replacement with a basic performance prepped 340/360 head. (375-475 hp head)