68 Swing Axle Rancho Upgrade & Replacement Advice

[Bug53]

I have a 68-restoration done by a previous owner. The body was near perfect but mechanically I had to do a lot of work to make things right. The engine runs well and has around 10K or less on it.
I have done mods. such as full flow, dual kadrons, clutch, some wiring, etc.
The transaxle however runs well through all the forward gears, and the reverse gear has a growly whine when backing up in gear but not so much with the clutch in.
I am guessing this tranny has a many many miles on it and without knowing the history of it all I am reluctant to beat on her or should I say drive energetically. LOL.
I want to buy a Rancho tranny or something similar that is a beefed up a little.
How much emphasis should I place on the axles themselves? Are these regularly replaced, rarely replaced, or another part that must be measured up?
Should I by default replace them just because I'm going with a new tranny?
Advice appreciated.
Thanks.

[Dusty1]

Comparing apples to oranges or maybe Macintosh to Granny Smith...

I went through half a dozen engines and half a dozen front beams in my old '67 as I piled on around half a million miles.

Several parts never, ever gave me trouble. They were and are

The transmission.

The starter.

The generator.

I lost track of the generator. The '67 pan, transmission and starter are under my '56.

If it ain't broke, don't fix it.

I might start to worry about the noisy reverse if I lost all forwards gears. It might bother me if I had to drive everywhere backwards with a noisy reverse.


If it were my car I'd eventually pop the body off the pan, weld in mounts and add trailing arms. One thing you can be sure of... most of the IRS transaxles you come across are newer than '68. I have a couple dozen of 'em including a few Thing transmissions.