Just a ball park idea will do.

it is tough to say with out pics, from the description and list of parts
$10,000 + at a MINIMUM, your car has some really nice selling points,
340 with EFI, gear venders, classic AC, disk brakes, are all going to increase the value tremendously, I would start asking much higher so you have some room to negotiate, depending on how it looks $15K-$16K yes the classic car market has dropped so it is hard to sell anything, not imposable, you need to ADVERTISE everywhere lots of pic's and be patient fewer buyers with money mean more effort on your part to find the right one,