how to make a 6.1 spin safely 7500 rpms?

340 is good for boat anchor as they make 120hp less than a 6.1 as they left the factory.
How many passes would a stock 340 have lasted at 425hp?
Its 2017 now not 1973

Anyway valvetrain is fine to 7500rpm if looking at the dragpak cars is anything to go by.....8000rpm onstock rockers