What sort of hp can the box and diffs handle comfortably thanks for any info

 

Comfortably between 225 and 280 IMO but also a lot down to how it's driven, ie lots of launches and hard on the gearbox is likely to end its life sooner. Mine is at 346 but I don't tend to do many launches. Torque is the main killer, mine is around 320 ft lbs which isn't to bad, newages boxes are stronger than classics but as I said its mainly how you treat them and how much torque your running IMO.