So, for future generations seeking to do this... The exotic freak u-joint I ended up using was... A stock Maverick rear u-joint. Apparently the bearing caps' size and distance apart are the same on both driveshafts. As for why I did this, there are a few advantages. Stability and strength are among them, lightness would be a plus but sadly I didn't get an aluminum one. I've looked for one for a long time and will continue to. Eventually I'll find one or have a more common one cut down. But I've been fighting a vibration problem for a few months. Tried new u-joints, tried clocking the yoke 180 degrees, nothing worked. It wasn't major, I figured I'd leave it alone until I found that elusive aluminum driveshaft. But then I changed the gearing in the rearend and suddenly that vibration is much more pronounced. Had to do something about it, the Mustang driveshaft is an upgrade and Maverick driveshafts are in short supply around here. Plus I figured that Mustang yoke with the damper on it couldn't hurt either. It solved the problem.
The dampened yoke is likely what took care of it unless you had a bent, warped or slightly out of balance driveshaft. I have been fighting the same gremlin and the dampened yoke is the next try for me.
The yoke has a metal ring around it with a thin inner ring of rubber, not unlike a harmonic balancer.
The one on my maverick has that. I assumed it was to fling any transmission fluid off to the ground that might leak from the rear trans seal. So, is mine different than most mavericks?
Don't know. I've never seen a damper on a Maverick yoke, but then I haven't really seen that many Mavericks relative to some people here. Maybe it came on later cars?
Mine is 74, so I guess 73 and up had them? Like a harmonic balancer, can these on the drive shaft wear out?
When I had my driveshaft straightened and balanced, the guy mentioned nothing about the balancer being messed up. Seems to run fine now.
Hmmm...looking like 73 was a transitional year for them. I love learning little tidbits of information like this, just so I can amaze my friends at the next party I attend. "Hey, did you know that they put dampners on driveshafts in Mavericks from mid-1973 onward?" "Uh, no, but I DO know that the human brain weighs 8 lbs...I heard THAT somewhere..."
Has anybody used the aluminum drive shaft out of an Aerostar van and just had it shortened? I'm not sure which years have the aluminum drive shaft though.