1973 k20 tranny swap

[chevykid71]

Hey guys I have inherited a 1973 chevy k20 camper special. My question is what would be the best transmission to use for a swap it has a built 350 turbo 3 speed automatic and 430 gears in the rear. I'm looking to just make it more fuel efficient for towing. The engine is stock with a slight rv cam. Only changes are carb swap to a holler 600 cfm. 65 mph= 3500 rpm roughly 6 mile to the gallon. Not to good on the wallet

 

[Rickf]

I am a fan of a gear vendors overdrive unit, I have one on a '54 1 ton with a TH400 and 4.10's. They are expensive, it may be cheaper than a 700R4 built for towing or a 4L60e with a controller.

 

[chevykid71]

Hey Rick I checked out the vendor gear overdrive website looks like the way to go versus changing the whole transmission since we have had this truck since new and had transmission rebuilt for pulling.