I got an e-mail back from the guy doing the V8 to GTP conversion(posted below). Sounds amazing.

Jack,
At this point it is a body sitting in the shed and the custom
frame is being built on the frame table. It is very involved as all
the heater box assembly and alot of the floor has to be removed. We
will be using a vintage air system that should fit under the dash on
the right side for ac and heat. Firewall has to be modified by being
moved back about 4" and a custom tunnel fabricated. It will be about
1 year in the making. We are trying for an almost stock exterior
(with the exception of the wheels) and at first glance, a stock
interior. The surprise will be when someone jumps on the throttle. I
am going to document it but will hold picture release till the
vehicle is up and running. Thanks for asking. John