I love that word 'best' because it always implies subjective judgments.

Best at what? What are you trying to accomplish?

The 2-speed Powerglide was an option, so factory parts could be used to make the swap if you can find them.

A TH350 will fit where a Powerglide did, so that is a reasonable swap.

And then you could consider one of the overdrive automatics.

But some idea what you want to accomplish would help narrow the choices.


1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...