vibration at 60 plus

well im new to the sight and have a question hope its in the right spot, i have a 94 cc dually 454, 5/7 spindels and springs, rear looks to be hangers c notch and bags over axle, it looks like (opps oh yah just got the truck) they pulled out some leaf springs also, they didnt finish it before i got it and it didnt have shocks on the rear, i got that fixed and it rides pretty good. it has a harmonic type vibration at 60 and above, it has a rear pinion angle that is downnot to sure of the degree yet but should it have anything that lowers the carrier bearing. im new to the lowered trucks thanks in advance for the input

Actually you usually have to raise the carrier bearing up to get some angle back into the driveline. When you drop you straighten out the angles and that abuses the U-joints.

Tire balance can come into play when you have a vibration at highway speed, so don't rule that out just yet.

Richard

yah i thaught of that i rebalanced all the tires and cked all the u joints its not in the front end its a harmonic type vib i dont know

Is your drive shaft still balanced?? I had a weird vibration on an old camaro years ago that turned out to be a drive shaft weight had slung off.