[Deadhead]

Yes. Custom shifts can be made for under $200. A few old threads have sources. Mine for my '63 came from a place in FL.

[cheese country GP]

Check your brake shoe adjustment. I had the same thing on my '62 GP & it turned out to be the brakes were adjusted too tight. Usually spin the wheels till they drag slightly & then back off a couple clicks. If you have 8 lugs, back off 10-12 clicks & that should do it. I know, seems like a lot but it did the trick for me. The pedal still only goes down about half way so plenty of brake left . I did the wheel straightening thing, rebalanced all the wheels, & then had the driveshaft checked for proper balance. Everything was just fine. Did the brake adjustment the way I've described above & the problem was solved. 65+ & smooth ride. Good luck

[pfilean]

Moving tires around and the other suggestions may help isolate the problem. You have to try something to know what to fix. And the rubber isolation in the drive shaft could go bad. If at some time there was a leaking transmission seal the soaked the shaft in oil that could have deteriorated the rubber some. But the symptoms you described used to be diagnosed as bad U-joints. Especially the front one. Something else to check.