'87 G-body (Olds 442) BAD vibration, help!!!

[kSStamp0182]

sorry for the post, i wasnt sure where to put it, cuz it is my Dad's car so i dont want to fool with joining a gbody forum & i'm sure you guys will be more help regardless, but anyway,

the car is an '87 Oldsmobile 442, with a '87 350 and 700R4 from a totaled R10 (both rebuilt & converted to carb, less thank 5k)

it has a BAD vibration that i have NO idea where is coming from, ive tried everything that i can think of. starts around 55mph, give or take a few, the speedo quit working not long ago (go figure). its bad enough you can see it in the hood and almost feels like the car wants to bounce off the road.

this is what we have done trying to chase this down.
-the rear (10 bolt 8.5") has been rebuilt because it had a whine, eaton LSD, all new bearings and richmond 3.73s.
-new rear bushings and UMI adj control arms
-rear bilstein's
-all new U-joints
-driveshaft was professionally shortened & rebalanced for drivetrain swap
-all engine/trans mounts are good & tight
-pinion angle is set with the rear and trans parallel
-all wheels are balanced dead on to 0.00
-new BFG radial t/a's



i do not know where else to look, the steering wheel feels perfectly fine even during the vib. although none of the front suspension has been touched yet (inspected tho, no visible signs of any damage)

the only thing we havent done to the drivetrain yet is install the torque convertor lockup, but i wouldnt think this would be the cause??

help me out guys!!


ohh & just cuz i know how y'all love pictures, heres the truck the cars motor came out of. RIP ol girl..