Trans opinions

[Baby Blue 66]

You mentioned that drive ability at highway speeds is an issue. A power glide, TH350, TH400 and your current 3 speed all have the same final gear ratio. I would think that you want either an OD, 200R4, 700R4, or or a manual box with OD. Or you could change to a numerically lower rear end gear or go with taller tires. I myself have a pretty thrashed 700R4 with 3.73 rear and 28in tall tires, makes for a nice combo. The hardest part of this install is the TV cable and a new drive shaft, you also need a flex plate and possibly a new tranny x-member, but is should bolt right up to a six.