Yeah...he is a friend of mine. He said it took him about 3 months to do it all, but he was only working on it on nights and weekends.
I think the hardest part was matching the flywheel to the transmission (trannys are in the rear of 928s).
It's quite a quick car for a 3 speed automatic (later 928 autos had 4 speed auto trannies). Manuals were always 5 speed.
With his 3 speed auto tranny, he was getting 13.5 100mph+ quarter mile times.....and he hasn't even tuned it in yet.
Here's a link to some photos another buddy of mine took when we all hit the drag strip this past summer:
928 Drag racing