I kept having the local driveshaft shop "fix" mine.

In the end it was cheaper to just order an all new Strange shaft with 1350 joints, new yoke, etc. from Dr. Diff.

No problems since!

'63 Dodge 330
11.19 @ 121 mph
Pump gas, n/a, through the mufflers on street tires with 3.54's. 3,600 lbs.
10.01 @ 133mph with a 250 shot of nitrous an a splash of race gas. 1.36 60 ft. 3,700 lbs.