[AZKen]

Funky: Actual Mileage, wow, that's nice. Date first sold 00/00/61 is weird? I wonder if yours is a left over 60? We can now call this post a Trivia Post. Your rivets are correct for 60. Other 61 trucks show a different style. Rivets were under evolution as were plates.

Anyway the holes were punched in that upper A pillar section at the Pontiac MI GM truck assembly plant which built GMC AND Chevy assemblies. Most of the cab parts were interchangeable, would have holes for Chevy and GMC plate locations and would all be designed to accommodate Chevy or GMC dash sections. The Pontiac East Plant was on a massive GM campus which included the Metal Stamping Plant (Pontiac Metal Center). The Pontiac East was shut down and some plants were demolished on the property in 2009. "The shutdown of the last assembly plant in what was once a central production hub of GM is part of the forced bankruptcy and restructuring of the US automaker by the Obama administration". GM filled bankruptcy in 2009, was restructured (bailed out) and in 2015 was said to be spending huge money to renew the Pontiac metal stamping plant where many of our trucks were built. It has taken all this time to recover from the past "economy". We, the people, spent $50 BILLION to bailout GM and recovered all but $10.3B. We bailed out Chrysler too. Ford did not ask for our money.


RE: 60-61 ID.
Pictures of a particular truck in question including dash colors and the trim could possibly give some clues.
Windshield/glass code/dates, and other small indicators could maybe, possibly distinguish a 60 from 61. Wheels would, hub caps would, heater maybe.