Trans swap 71 Malibu

[al71]

I have 71 350-270hp with 350 trans and 2.73 gears. At 60 mph I am at about 2200 rpm. I would like to switch to an overdrive trans. What would be a good swap and how can I determine what my new rpm would be? Also I would like to be able to shift between the lower 3 gears, is that possible with the handlebar shifter? thanks al71

[67-ls1]

I believe the 700r4 would be your best bet. In forth gear (0.70 od) your rpm should drop 30% to about 1540 rpm.
There are vendors that offer different shifter detents and even the faceplates to use your stock shifter with the 700r and be able to shift each gear.