I have done the 8v engine, not a big job takes longer to get under tray off than change shaft. Tarquin says it's m32 gearbox in 150 bhp model, I haven't done one yet, but happy to do one if there's someone local who wants it doing. I have 30 years in motor trade and last 22 years working for gm. Keep my hands in at the weekend to de stress! You repairer would need to remove the shaft an measure diameter of spline, and compare with the vectra shaft, I have an f40 gearbox shaft so can tell you diameter of that and m32 gearbox. To do it buy both shafts, including the bracket on the shaft that bolts to the sump. The vectra is a two piece shaft on os, simply remove shafts And swap them. Top up gearbox oil 10mm Allen screw easy to get at, and off you go no more shakes. The car I did was transformed, it was horrific between 40 55 mph. Note there are thousands of vectra's in the uk. The driveshafts I got had done 40 k and they felt like new.