How rare is this truck?

[DLCNC]

I'm going Monday to pick up a 72 GMC Stepside. It has factory air, power steering, power brakes and factory tach. Everything is original except for the engine. It currently has a 327/300 with headers, aluminum intake and small cam. The AC compressor comes with the truck but isn't on the truck since there is no way to mount it with the double-hump heads. Plans are to give it a good detailing and maybe change the heads so that I can put the AC back on the truck. It has some rust in the rockers but other than that it is pretty rust free. Also, it doesn't have leaf spring rear suspension...I thought all GMCs back in the 70's had leaf spring suspension. I'll post pics once I get it home.