It's a regular short-bed...the whole truck seems much smaller than my '61!
The crossmembers were cleanly removed; it looks like a PO drilled the rivet heads out, then hit them with a cold chisel, just like the shop manual says. The rivet holes are not deformed at all. The existing tubular aftermarket crossmember visible in the photos is bolted in...looks like using the existing rivet holes.
The shop manual says hot-riveting is the recommended method of re-attaching a replacement crossmember. I don't have that ability, but I'm guessing that bolts or welding would work just as well. With so many people replacing the stock crossmembers with SBC/TH350 compatible ones, you'd think there'd be extras somewhere!
-Kevin
