My '70 Jimmy's TH350 has a leaking front seal. I've convinced my wife it needs to either be rebuilt or replaced. Question is, for a weekend driver (maybe sometimes to work) is it worth swapping to a 700R in place of just replacing the leaking seal? Are the trannys from Jet a good quality? I like the idea of a lower first and the extra gear, but the cost and modifiactions required may not make it worth while.