I went to see the guy today and got some good parts and also saw the truck and motor. The truck was an original 6 cyl truck that the original owner put a 265 in. It did not have a V8 stomp starter setup. There was no linkage on the bellhousing. The engine did have power pack heads, but I couldn't tell what the casting or date code numbers were as the valve covers were still on it and it was wrapped in shrink wrap. It had a 4 bbl carb on it, so I guess it could be a power pack engine. The crossmember V8 brackets were added on using carriage bolts and not the factory rivets. After talking to him, it appears he was confused about what was original to the truck.
The 58 project truck is about 70% done and looked to be a Cameo. It has a cameo bed on it, but I didn't see the VIN to be able to determine it to be an original cameo. he told me the bed was reproduction, so I'm leaning to it NOT being a Cameo. It has a 350 engine, Camaro rearend, later model steering column, bucket syle seats
V8 with Power Pak heads and 4bbl carb would have come out either a Passenger car or Corvette, they were never offered in a light Truck (4bbl carb was an option on heavy duty 2 ton and larger, though).
On the '58, unfortunately, they did not include anything in the serial numbers to differentiate the Cameo from any other truck. As you mention, reproduction beds are available, so it very well could be a conversion.
