Again, my 54 was helpless with the open 9 inch. In wet weather I had to wait for a huge break before pulling out from a side street, or risk getting t-boned. I love my 8.8 limited slip and the disk brakes let me avoid buying a new proportioning valve.

 

I really appreciate all the info & help.
Will the 28 spline work with a limited slip?
TractormanBill

 

A 28 spline limited slip 9" will work, I have one in the Mustang and the 48

 

Is it a big deal to put an aftermarket limited slip in a 9" third member with 28 splines?
If not any brand suggestions?
TractormanBill

 

No, it is easy to intall the carrier of you choice. There are several good choices depending on how you are planning on driving the truck. Unlike what das54 said there is nothing wrong with a single legger and it will accept any gear ratio.

 

I had a '62 TBird that was like DAS54's, it would spin the one tire (RR I recall) without any provocation. It got stuck on flat level ground with an inch of snow once. It was because the opposite side rear brake was dragging, due to the e-brake cable being frozen up. Made all the difference in the world to fix the brakes.

 

Let's say I come up with a 1972 9" rear axle with a ratio I like, is it realistic to install an aftermarket limited slip in it.
Will not have a hot motor (just stock 302) or be used for drag racing with a C-4. City Streets & highway only.
TractormanBill

 

Is it realistic? Only you can answer that.
If I had the components you have in hand and found a complete rear but a peg leg, I'd use it. For driving on the street I don't think the expense of buying out weighs the benefits.
72 was the last year of the f-100 rear that was a straight swap. Broaden your search in the years from 64-72 and you will find what you want with posi.
A way to identify 28 spline from 31 spline is in the center of the hub plate on the axle there is a oval indention, on the 31 there are two round indentions
Find old farm trucks the farmers loved the posi to help pull the loads