A few years ago, I thought long and hard about what to do to make my truck a better highway driver. At the same time, I didn't want to give up the advantages my sm420 has. In particaular, the granny gear and the fact that driving around town in 3rd with a 3:90 rear is the next best thing to having an automatic. So... I've been saving my money for a couple of years, took a second job, aggravated the sheriff, and bought a gear vendors overdrive. I just got it last week and am in the process of pulling and rebuilding the sm420 before I marry it to the O.D. I believe that will give me the best of both worlds. 4th over will be the equivilant of having a 3:09 rear. At 3k, it has put me in the poor house (and the doghouse) for a while, but I think it will be worth it. I've sacrificed nothing as far as low end power, and living in the land of steep hills and boat ramps, that makes me happy.
