Low Speed Vibration

[NorthWolf33]

Hey I just put 33's on my 1990 Full SIze Blazer and a 4 inch lift. I also changed the driveshaft cause mine was missing a piece out of it. Also just after I put the lift and tires I got into an accident and bent the front driver side corner frame. I got the frame bent back to normal so it still needs a front end alignment from the accident and with the new tires on it. But ya thats the details and so now today I got it goin again and drove it and when I get goin there is a vibration at low speeds but once I get goin up around 30+ it smoothes out. So my question is what could possibly be causing a virbration at low speeds. You can feel it throughout the truck (floor, pedals, seat, not so much in the steering wheel.) But ya any suggestions on what it might be?