if i get over 70ish at first it gets a feeling of floating and then a constant vibration i feel in my shifter. i have a t-56 that didn't have issues before i swapped a new rear end in there the other day (which is when this shake started)

if i put the clutch in i still feel it shaking bad in the shifter. so it's not motor related and i doubt tranny related because like i said i just did the rear end swap

the car would shake before the swap but not anything like this, i had a slightly bent axle before.

so far to correct my vibration i've done the brakes (new cylinders, shoes, and drums)
checked driveshaft/ujoints (no play) can it be flipped 180 degrees and be unbalanced? i havent tried flipping it.
all bushings are good (panhard, torque arm, control arms) and all bolts are tight.

the new rear end is a 10 bolt 3rd gen 3.73 posi built 15k ago or something and i put 75 90 mobil 1 synthetic in it til it came out the fill hole.

i'm needing tires so i'll be checking the wheel balance soon, but any other clues you guys can mention?

 

Hmmm...sounds like a bad bearing somewhere in the rear end assembly. I'm no expert, though.

 

any more suggestions?

 

I really don't think you'll get that improved much more. make sure your wheels are balanced and tire pressure's are all what there suppose to be. but it really seems to me that it is a suspension issue. my has done it for years now, there just old cars. unless you wanna shell out some money for and suspesion rebuild, new bushings make a huge diff thought. It wouldn't make a difference if your drive shaft was flipped, it still rotates the same direction regardless, as long as its ballanced. double check your new rearend. no bent axel, fluid levels good. that kinda stuff.

 

You didn't mention what kind of T-56 you put in, but if it's one of the newer retrofits (so you can use the standard clutch and bellhousing along with mech. speedo), then it's roughly 2" longer than the 700-R4 or T-5.

This means your pinion angle could be off, which could cause the shaking.

http://www.carcraft.com/howto/91758/index.html

 

its a lt1 style. but it wasn't bad before the rear end swap, now it's terrible. i would think pinion would be the same since the torque arm is the same