i spoke to the guy in s.a with this conversion, all that was needed was custom tailshaft, gearbox crossmember and engine to mounts were custom. I think he had standard engine mounts from the crossmember part. very easy from what i saw. I am doing this conversion myself on a r32
there is a place here in sa that makes mounts for ls1 conversions, he is on ebay. best bet would be mounts for the vl 6 cyl range.
hope this helps