I built that kit as a kid. If one came along at the right time, I would get it. The body was pretty nice. All I remember about the interior/ chassis is that it was a stripped race car style. Racing seats and a spare molded into the rear . I think I still have the engine, its an engine in the figurative sense in that it looks like an engine, but nothing specific where you can tell what kind of engine it is.
The work you're doing is amazing! Although, I'm not confident a turbo'ed 2.4 litre engine would be adequate for powering a 43 year old mid-size hunk of Detroit iron. Put that in a Colt, Omni, or Rampage, then you'll see everyone in your mirror.