with just bolt on parts such as the ones u list id say 210 mabey 220. and yeah i think it would handle a 75 hot with proper tunning. ive seen moderatly built gsr motors running 400+ on pump gas. i recently saw a 2000 gsr with 827 whp and 518 lb-ft. it was built out the ass of coarse but with factory type r camshafts. its a good motor to work with.