If he has bad vibes, a MML will not change the angle by enough to take them out.
Im guessing he put in enough tilt when he welded the SOA perches and that the driveshaft isnt running at equal angles on both ends.
If he has lift springs, get some stockers until he can SYE it.
If he has stockers, drop that rear shaft for now and pony up for the SYE.
A normal 2 joint shaft needs the same angle on each joint. As in if total angle is 10 degrees, each joint needs 5 degrees on it. Which about max for a single ujoint by the way.
A CV shaft works differently. You point the pinion straight at the t-case output with a about 2 degrees max on the pinion ujoint. Downwards, to accomadate for axle wrap.
The CV knuckle takes up the rest of the angle.
If he tilted straight towards the tcase with the SOA, there isnt much he can do to get a 2 joint shaft to run right, other then drop a lot of lift out of it.