SB2.2 heads are AMAZING. The flow numbers are incredible.
They are made for hi-rpm. And yes, they have been around a long time.
I seen a mid 90's Camaro with a 394cid SB2.2-head motor just devastate a 70 Nova with a 555cid Brodix-headed roller motor. The Nova had NO chance against the Camaro. I'm talking like a 15 car-length difference in the 1/4 mile. Neither car was running power-adders. The Camaro had a single 5" exhaust pipe out the back. It was one sick ride.