hi ive just put a newer engine and trans in my blazer after it has sat at a shop for 3 years. i just had the transmission rebuilt since my junkyard cert. trans went out as soon as i drove it around the block when i put it in. i intern at a chevy dealership but i want some opinions before i have them tear into another part of my car. it drives great until u get to about 50mph and then as soon as your anything faster then 50mph when u let off the gas it vibrates. its not violent but i don't want to mess anything up. when it was getting smogged i notice the rear wheels (both) wobble. now is it possible that the axle shafts are somewhat bent from sitting? because i tested run-out on the rims and they are fine. please any opinion will be taken gladly

 

There is no way that just sitting around bent the axles. Now, that isn't good on your tires. I would have the tires road force balanced and see what the results are.

 

the rims that it had were stolen. so i had my irocs and im getting new tires. would there be anything that could cause the vibration in the rear end?

 

check the driveshafts and u-joints.

 

those tires still might need to be balanced.