Yeah I thought the same!
I took it down to the local Autoco and ut it up on the hoist - turns out the previous owner had broken the engine mounts and just welded them back up - they look to ahve broken again - he welds them again.
The whole engine had moved over by the looks of things, the tail shaft was sitting on an " / "angle. We straightened the box up but it will move again.
The car had the box reco'd about 6 mths before I bought it, and I did the centre bearing about 2 months back, bloke at autoco recons he had them doone because the tailshaft being on an angle had shagged the bearings out, I dont know why he paid $1000+ for a reco, and didnt spend an extra $50 on mounts to fix it altogether, but who knows!
Im going to Repco today to get 2 new mounts, $33 each, or $24 from holden, but apparently the Repco onnes have a higher grade rubber, plus they are in stock, so thats where im headed.
Tell you what though, its a totally different car to drive, even just doing the mounts and moving the box! Absolutley no vibration at all, even at low revs (used to have bad vibs, bu my VP did that too so I thought it was normal!)
Anywa thanks for the suggestion mate, going to do the mounts tomorrow.