There's a guy from zdriver and I think he might post here as well, by the name of "BobsZtwins"
One of his Z's was originally a scarab, But I believe I remember him posting that he relocated the engine and placed it farther back towards the center of the car, and also turbocharging it.
I'm no purist but I think if you aren't planning on auto x'ing or aren't serious about racing it, then keep it in good shape, let it appreciate, enjoy it and drive it!