That is pretty cool. Always loved those big old wide-trac Potiacs. I can't tell from the photos if there is a working tailgate or it is just a cargo box. Not crazy of the roof line around the rear window. I still like it!
That is a pontiac motor they all are the same basic size just bigger bores. Don't see the tri power so probably just 4 brl. Should be painted blue not chev red. They had a 326 and 389 around those years and they went pretty good.
great idea, but i don't think it was carried out very well, flat back window and a couple other things just don't quite look right(i noticed the hinges too) but the great thing about this hobby is if you like something, screw what everybody else thinks!