The cab is GMC because the Kick panel Data plate/Vin plate is legit and original. The A pillar Plate is a home made sketchy plate used by people who have a title and want to match the number with the title. If it was not done thru DMV, the truck is illegally titled and registered.
The style, location and Vin on the kick panel plate indicate 1960 GMC cab. I agree, a Chevy cluster and dash. (Bow Tie on cluster.)
Big window cab is money.
What motor is in it?
Torsion bar front suspension or coil? 1963 last year for wrap around windshield and first year for coil front.
A Chevy frame will have a partial VIN stamped on it, a GMC will have no stamp.
