There should be no play between the output shaft from the gearbox and the drive shaft i.e. over the flexible coupling. I could not detect any play on the coupling even although it was faulty. It showed up as a vibration at high speed and a slight "clonk" sometimes when engaging gear.
I agree with Larry the worst part of the job was having to lower the exhaust. Rather than part the exhaust I lowered the whole system from the manifold back. Oh and I am also lowering my head,obviously I still think in terms of solid rear axle suspension.