I have a set of their assembled heads and stainless rockers going onto a stock bottom end budget 360 build for my wagon. Hoping to have it running by late May, just waiting on some parts right now to finish the motor.

I had their air gap copy manifold and returned it after reading it leaves close 30hp on the table compared to a real air gap...Ended up with a single plane instead for my build, but some parts don't justify the savings benefit in my opinion. I was going from 318 iron heads with 1.77" intake valves that I sold for $300 local, so the $900 for the assembled Speedmaster heads were a no brainer, and so far on disassembly they have checked out okay.