Here is a bolt on for Porsche 930 style CV axles

https://zcardepot.com/collections/rear-axle-and-differential/products/billet-aluminum-cv-axle-adaptor-930-240z-260z-280z

Oops. not the right part.  You need the flange, not the axle.

The u-joint axles are plenty strong.

Edited January 13, 20205 yr by Zed Head

Here are some flanges.  Not sure he has stock though, he makes them in batches.

http://www.chequeredflagracing.net/Datsun.html

Thank you for the parts options.