Allroad vibrations after engine out and other changes - looking for ideas

[vtraudt]

Car is 2003 Allroad; in 2014 converted from auto manual (A6 tranny, diff, used OEM CV shafts)
No vibrations noticeable prior to engine out and other changes.
Now have noticeable vibrations:

Just writing down what we know:

- car had no vibrations when it came
- engine, transmission, subframe removed as one unit
- front left drive shaft replaced with new ftermarket A6 unit
- original used A6 front right still on car, stayed on car during work
- propeller shaft disconnected at transmission and stayed on car during work
- rear diff stabilizer installed
- adjustable upper control arms installed
- BC coil overs installed
- solid sway bar bushings installed
- hotchkis swaybar installed
- new tie rods installed
- new wheels/tires installed
- engine/transmission/subframe installed
- alignment done

Car vibrates at various speeds, even below 50 mph; coasting, neutral or under load (if anything, less under load).

installed old OEM wheels/tires. Vibrations less pronounced, but still present.

Looking for tips, suggestions what to try next.

[alien_brain]

the end links are solid not the sway bar bushings.

the wheels are new but the tires are used

[glennda5id]

I would suspect the replacement axle. Are the A6 axles the correct length for the allroad?

[allroad_22]

I'm fighting vibrations on my allroad as well, also converted to manual, but mine are almost completely from old tires sitting too long and only noticeable above 60mph. Tire shop informed me that they are as round as an egg... With that said, I've been considering other things as well, so let me ask you a few questions to help diagnose:

1. Does it vibrate under accelaration or even under coasting?
2. Is the driveshaft new or rebuilt?
3. What frequency would you relate the vibration to be at 50mph? is it like a big fan? or like a washing machine that's out of balance? Would you measure it in hertz or kilohertz?

[alien_brain]

vibrations are gone and were due to the wrong size hubcentric spacers. bought new ones the correct size and voila, were cooking with gas again