My a14 wouldn't rev past about 7250 ish, with a hitachi carb , piss weak compression and a forcrce feeding cam grind. I have dual valve springs all set up to instaled heights. I was thinking that the points must be bouncing. Once the blowers on (this weekend all going well) I wont need to rev it harder than that, but it's still nice to know that I could if I wanted to.
Oh yeah, another trick for big revving donks id replacing the springs betweem the rocker arms with bushes, this stops the rocker arms migrating and bending /breaking push rods.