i can get 50+ out of mine easily with the 228 or the 270 with a 4:56 timkin rear. your out of motor. like cris asked what rear you got? i have a brownie jr od on mine but just took it off due to the noise it makes. i think an overdrive is not worth the gain vs the costs of engineering and installing it these days. i havent done one because im not able to but gear swaps are much cheaper