It's tough to tell from one pic but questions you should be asking are how much rust on body and chassis? Having a 403 in an
H/O will reduce the value for purists...Is the head gasket the only issue mechanically? Which transmission does it have and was it set up to handle a 403? (a stock OZ trans likely won't last long behind a 403). How much of the car is original? Are the lightning rods there and functional? Is the rear wing missing parts? Rims rusty or bent? Interiors can be expensive to restore. The 83'
H/O has the small 7.5" rear end so if you have plans for hi HP/Torque numbers plan on upgrades. The body looks rough in the pic. Keep in mind you can buy a really nice 83'
H/O that needs nothing for 12-15K...maybe less if you find a good deal.