Technical Cad 331 manual transmission options?

I'm getting started on a '50 Cad ambulance project. It's has the early integral bellhousing block and stock 3 speed. Motor will need a full rebuild, but I found a '55 331 in running condition.

If I run that block, I'd have to get the Wilcap or Speed Gems adapter, and run a GM transmission...

I plan to actually use the car for shop hauling and to pull a light car trailer. Would like to keep the rest of the chassis stock except for brakes. Any transmission suggestions besides a Muncie? For period correctness, a Borg Warner overdrive might work, but would it hold up to the weight of the commercial chassis? T-5 or NV4500?

 

Since you plan to tow the NV4500 would be a good choice,it might look out of place in that Caddy but in Cuba there is a 50s Caddy limo running around with a truck 4 speed and it is powered by a diesel.

 

Nv4500 has a different trans bolt pattern than standard gm meaning it has its own specific bell housing. It’s big and heavy. The dodge ones have a longer input. Makes it easier to adapt.
A nv3500 may work better unless your putting a goose neck in the trunk.
I wouldn’t tow much with a t5. Nothing heavy anyway.
I’d look for a 1/2 ton truck 5speed set up.
The nv3500 can be found with a standard gm bolt pattern.

 

I hadn't thought of the nv3500, thanks! I was never a fan of newer trans swaps until I drove a '54 Packard with a 359 straight 8 and a T5...it was a really slick setup.

 

Gm had a wide and close(er) ratio version.
There is an HD version with a tail shaft parking brake.

 

If I was not chicken I would do one in my '50 Buick

Ben