vibration at 2200 rpm

[LandTug2]

Hey guys, I have had some vibration issues around 2200 rpm that I can hear and feel in the gas pedal and wandered if anyone else has run into this? It seems to be rpm related as I revved the engine up to 2200 rpm in the driveway and had the same vibration. I also tried it with the clutch pushed in and with it out with no difference. I did some research and saw people have had this issue related to u joints but that would only be the case if I had the vibrations only while driving correct? I also heard some weird harmonics could cause it.

I have an ATP super damper that I put on the truck and am currently not running a fan either.

Anyone else run into this?

[wilkyflex]

In my case, after I rebuilt the engine, I noticed I had slight vibration. there are three possibilities, which I am trying to figure out.
1. pistons could be different weights, but unlikely
2. could have accidentally mixed the caps to the wrong rods
3. vibration damper failure

Just ideas for you.
Thanks

[BILTIT]

When did it start? Have you done anything work on the truck in the last 6 months?

[wilkyflex]

Yes. I rebuilt the entire engine. It started right up and runs good. but it's got a fast vibration that makes the body shake. Not alot, but definately something isn't right. help?