cubs would be a waste of money for what you wanna do..you really dont even need to go 4mm..a good low end port job is all you really need. eric gorr does an insane woods port that has so much low end grunt its not even funny...i guarantee that setup would never let you down on those steep rocky hills. my bros setup was, gorr's woods port, t5's. noss head with 18cc domes, 33mm pwk, vf2...he could pull 17 tooth front sprocket like it was a 14...this is the route i would go...