OK so I just got my Marlin crawler in and it rocks. Had my driveshafts re-done, rear one shorter, front one longer blah blah blah. Ever since I put the shafts in, I'm getting some very slight vibes at 2200rpm. I've been trying to think of what is vibrating at certain RPMs. Driveshaft? Extra noise/vibration because of second t-case? It's a seat of the pants vibration, any help is appreciated!

You just changed the angle on your rear driveline to a higher angle.--take a look at it. You may need to shim your rear housing up a couple of degrees. Also, you don't say what gear you are in at 2200. Is the vibration related to roadspeed or engine speed. If it vibrates everytime you run thru 2200 in any gear, odds are on an engine/clutch issue. If it's at a given road speed it would point to tires/driveline. The transmission and T-cases are not pron to vibrate and should not make any additional noise until you start dropping ranges.