I'd agree with milling the back of the transmission bell. The U joint pivot is a slip fit in the spline, so the pivot point won't change enough to make a difference. Mill it enough so you need 3 or 4 gaskets to get a snug fit, so future wear can be adjusted out. Be sure to keep the U joint housing lubed well- - - -don't depend on splash from the main case. Good luck!
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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