School me on the 4 speed, please.

Well, theres 6 to chose from, so to speak. The 4 spd came in cast iron and aluminum, overdrive and not, long tail and short tail. Then theres 2 bearing retainer sizes.

You'll need to find the short tail iron one to be correct. I do not remember the bearing size retainer for your car. At least the correct one.

The trannys also came with an overdrive. The first gear is deep @ 3.09 *I think* first gear and a .67 *I think* overdrive ratio.

Aluminum versions are out there, but can be hard to find and expensive to purchase.
I'd go to a die hard MoPar man for my tranny. And speak of which,
click here;
http://www.passonperformance.com/

Passon also has his own overdrive set up which is stronger than the OE way. He's been doing these for years.

I could be wrong but I thought there were three bearing retainer sizes. The two smaller ones and the huge od one.
short tail is a/f and long is b/e/pu. http://www.slantsix.org/articles/4-speeds/ODA833fourspeed1.htm