It has a 427 CI SB. Looks nice overall. Good looking suspension. I noticed the shift linkage was not connected and it had 2" ground clearance so I don't think it is a driver.
I would hope it is a pre-production piece as it had some odd things about it. Some of which have been shown here before. The front chassis mounts for the upper trailing links were aligned straight front to back (not angled outward in the direction of the links) which is causing the trailing links to bind, contact, and bend the chassis mounts. A couple of places showed rust in the crevises where the chassis is put together, and thus I assume this is made of mild steel.