I used a VL diff in my old VH, and used the rear half of the VK borgy tailshaft....didn't run into any probs....since then I sold my VL diff and we've got a few VK borgy diffs, which have bolted in the same with the same tailshaft with no probs.....so altho I don't know for sure if they're different, I'm 99.99% sure they are the same....they'd have to be....the only major difference between them is the gears and the VL diff is slightly wider.
I had a stripped out hole for the centre bearing.....was also in my old VH.....my uncle helped me fix it, I rekon he rethreaded it with a tap and die set. If worst comes to worst, pull up ya carpet and drill out the hole, weld a nut to the floor and put new bolts in underneath.