Mopar R1 block

we ran GK mushrooms in the AMC trans am car
they really work but are a real PITA during development
actually the increased acceleration is due to starting the sweep further from the center of the lifter
it can actually be less "agressive"
and a mopar size profile can be less agressive than a chevy and till have more acceleration
old wives tale that .904 profiles are harder on parts- but of course you can build a cam that you have to change spring on often with either size lifter- but with the mopar lifter you do not HAVE to to beat the chevies, who are also handicapped by their short rods
for example both Crane and Engle had 3 series of lobes god knows how many comp has
I'd call them streeet, street strip and trailer