The steering shaft is my biggest worry. I've seen a HB with a setup exactly like you are talking about, with the IRS and VG30DETT, but the twin turbos were swapped out for one bigger turbo. That thread is on here somwhere...I remember the steering shaft having some crazy angle, but the builder/owner said it worked fine.
Found it! It's actually a VQ engine, but still very similar to your idea.
zer...dbody
Modified by seang at 7:47 PM 11/29/2009