Is a automatic trans possible for a 236 straight 6?

[Isaiah92260]

I’ve read a few past conversations on here but it was about going T5 and changing the read end

I’m hoping to learn something here.

I don’t know anything about gear ratio’s or transmissions.

Reason being for asking about a automatic transmission is because I really enjoy having the concept of column shifting.

I have a 1961 with a 235, 3 speed in the column and whatever basic rear end they put in a base model short bed Apache.

I could only go about 50 on the road without hearing the motor get pretty noisy and noticing the engine temperature starting to get warmer.

If I were to go automatic, what is the best tranny? Tom lagdon I read says no to a TH350.
But a 200-4R? What about a 700 r4?
Do I need to alter my drive shaft? And can I keep the rear end but just have to open it up and replacing it was a different differential ratio gearing?

If l have to go with a T5 because it’s just makes more sense I guess I will have to.

What ever is easier I suppose, I don’t want to go v8. If keep the 3 speed but changing the differential is good, that’s cool, transmission and differential swamp then? Okay which combination?

This is now becoming more of a priority because now that my 235 is running good and I have new tires, and brakes done, I’ve been driving it a lot more during the week and the weekends, I feel like I need to keep up on the road.

Any ideas and advice is greatly appreciated. Thank you all!