How often or how many hours till they need new rotors and a $8,000 rebuild if you know ? contemplating ordering 8.3s but I know these make some huge horsepower

I would guess every 200 hours they should be serviced. Only need rotors if they get damaged

Sounds fair, prolly have to send them in every winter for preventive maint as sounds like the bearings went away and rotors ate em up. i'll call whipple and see if hes got a set of intakes on the shelf to complete this set up while on lock down for this BS Virus

Actually no they were rebuilt for peace of mind. I ended up changing my builds. There were on Merc 900sc motors when I got them