I have a 91 chevy silverado k1500 4x4 with a 4.3 v6 manual 5spd. It has 196000 miles is it worth it when it takes a crap to replace with a 5.7/350??? And I was wondering if I took 3/4 ton leaf springs would they mount right up with my stock mounts??? Oh and the motor revs high how can I fix that. Other than that the motor runs great. Let me know thanks