iI've used them in my old E85 bracket motor with 15.0 to 1 compression ratio with a MSD 7AL2 no issues up to 7300 RPM shruggy
Same thing on the new black caps like them. I do prefer the older ones with those ribs in them but I haven't been able to find a reliable source for them in the last five years whiney shruggy

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)