For what is worth, there was a 66 hardtop here with a nitrous boosted 230 and I am not sure of any additional details, but it was a all steel and full interior street car. He ran mid thirteens here which would have put it very close to the 12s at sea level.
I would guess if your friend is thinking of a LS1-LS7 type motor, he is going with an aftermarket front clip. If he is planning on that, then it opens up all kinds of options with an inline space wise. With a clip, he can fit 3 Webers, a roots style blower and Vortec style superchargers become much easier.
Also, check out the Camaro at
http://www.goravenswood.com/engines.htm It is in the 11's; Twisted knows the car as to whether it is anywhere near street able or not, but it may help sway your argument.
