Help, can I change input shaft on Doug Nash 4+1 transmission?

I needed a trans to complete my 34 truck build, my dad will trade me a Doug Nash 4+1 trans that is like new. Problem is it was setup for a 426 hemi and has a 18 spline input shaft. I am running a Pontiac motor that had a th400 Can I change this? And can I possibly use Richmond parts since they bought them out? I like the ratio and strength of this trans.

Thanks, Kail

 

I'd call Richmond and ask..My memory says Mopar was the oddball in ratios so the input may have different tooth count than GM but mabe the cluster drive gear could be changed too....Maybe and adaptor/bell housing?

 

Use an 18 spline clutch disc and GM pressure plate.

 

beat me to it!

x2

 

The GM input shaft is 6.66 inches long. The Mopar is 8.57 inches long.

 

I've got an old Super Stock Mopar trans that was built to go behind a Chevy: they turned down the input shaft length and pilot diameter to fit with a Chevy bellhousing (I have a blow-proof lakewood that had Mopar mounting holes added to it)

I don't know what the front of the Doug Nash trans looks like for your application: you may have to have an adapter made, which I would guess will be 1/2-inch or maybe 1-inch material.
Take the trans apart and have a machine shop turn the input shaft down to the right diameter, then go with the 18-spline clutch disk.

Also, I would imagine the bearing retainer on the front of the trans will be the same diameter as a Mopar piece, to register in the bellhousing's hole.
The Chevy is a smaller diameter: on my S/S trans, and the New Process 4spd OD in my Suburban, that bearing retainer O.D. had to be turned down .250-inch to fit a GM bellhousing. I also had to use four allen blots/cap screws to retain it, as the heads on hex-head bolts interfered with the hole in the bellhousing.


-Brad

 

Thanks guys. This gives me somewhere to start. I emailed Richmond today as well.