Drive line vibration

[454chevy]

Between 1600-2000 rpm I have a "slight" drive line vibration/rumble on my 1976 C10 454CID.  I have new bearings and universal joints.  Th400 transmission.  New torque converter. New pinion and rear gears and bearings.  One or two guys has suggested changing drive shaft angle.  Someone has also suggested I might have a damper going bad on the engine.  It was new 5k miles ago.  Appreciate comments and recommendations. 

[77c15]

If it is lifted you may have an issue with the pinion angle, but it sounds more like a driveshaft or tire out of balance. After spending a couple of hundred dollar bills to get my driveshaft rebalanced locally, I found out that my right rear wheel was bent and only at a certain tire temp and speed did I get a vibration.

[joesgarage71]

 There is a bushing in the tailshaft of your TH400 that might need replacing.

 Steve

[VileZambonie]

If you suspect it's a driveshaft balance problem simply put a hose clamp on the driveshaft and it will act like a counter weight. You can try it in a few positions and clamping down on a few coins to add a little more weight. If this effects your vibration then you know it's driveshaft related. If not then you're barking up the wrong tree.

[454chevy]

Thanks for all of your suggestions.  Finally figured out the problem.  It was driveshaft angle.  I had installed CalTec like traction bars on a mount I designed.  Angle of axle was changed too much.  Had spring mounts unwelded and moved to correct position on the axle.  Very smooth now.