I found a new driveshaft for a 2000 RT dakota, std cab version....
It should be perfect for my 89 short bed with 5.9L magnum and 8.25 rear end. The 8.25 and 9.25 have the same nose length. BUT, I have moved the engine back about an inch. I am hoping that I won't have to shorten the driveshaft....
I am assuming that if I put it all the way in, and then pull it back out til the rear flanges meet that I need a certain amount of "pull back".
Anybody have experience with this kind of thing?

 

Yes there needs to be a bit of pull back (I'm sure there is a better term). An inch or so, usually there is a mark on the yoke that you can tell where the old seal ended that might be a good point to measure from.

If you do need to shorten it, I know my local driveshaft shop does it for $80 with balancing. So it shouldn't be to bad in other shops.