Driveshaft on my 66 valiant fell off. Now what?

Hehe, ya, if only i had got it off the side of the road that night. Now i know what a driveshaft sounds like when it falls off.

Well, i jacked it up and put a tape measure to it. It looks like its 54" from taleshaft to differential saddle. Does that sound right?

Also, there is 1/2 a u-joint on the differential side, so it appears i found the failure.