Ok, be difficult then
With no pics I'll go on some assumptions: It's a stand up "driver" quality car with some miles on it but looks good, on a 1-10 scale let's call it a solid "7".
Good stuff: 440+6, 4 speed, Lime Light Green, Dana 60, RARE!
Bad Stuff: None original engine, with new paint rust history is a guess at best and may rear it's ugly head someday. Rust repair, sheet metal replacement, body work and paint, can be VERY expensive! Probably the single most expensive cost when doing a car. If you discover rust or shoddy repairs (if you can see ANY evidence of prior body work consider it "shoddy") then the value will RAPIDLY spiral down (by many thousands of dollars)
Things to look for: Check numbers on the transmission and rear end, be sure it has a build sheet and or a fender tag. Check the date on the engine to be sure it's at least period correct. Check for fresh looking undercoating (often used to cover rusty floors!) POR 15 IS NOT a correct rust repair method! If it get's mentioned at all start looking REALLY hard for rust repairs in the floors, trunk, and around the rear window and quarters. Look for frame damage in the engine bay and front header panel area for prior accidents (4 speed cars seemed to land in ditches allot back in the day and generally have seen a rougher life than automatics)
Drive the car to listen for clues of any mechanical problems.
Now, if all is well? I'd say I agree with the Captain around 25k. BUT, as he said.....It REALLY comes down to how much you or someone else is willing to pay, it never hurts to start low (15k or so)
Also, since it's not a true numbers matching car it will never be worth 100% of what a numbers car is worth no matter how much you invest into it (maybe close but never equal) consider this for future resale value.
My last bit of advice? Take a GOOD body and paint man with you to look at the car, it will save you allot of grief later to know what you are getting into up front.
Good luck!
