Driveshaft balancing in Calgary or nearby?

Hello all,
I suspect the drive shaft on my 78 C-Bod might be out of balance a bit, or (worst case) it is bent a bit - there's a driveline vibration at 105-110 km/h (65-70 mph). New engine/transmission mounts, new U-joints... I am playing with the clamps per the shop manual, but have not succeeded yet.
Will appreciate any leads to a reputable shop to check/fix it. Can't fully trust the google reviews these days...
Thanks in advance!