lots more involved than 'swapping out' some parts, not sure a GMC gauge cluster would even fit in a Chevy dash, not to mention frame and powertrain differences .... I'd bet someone simply put the tags and papers from a GMC onto a Chevy truck that didn't have proper registration - not really an uncommon situation with vintage vehicles

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir
"When we tug a single thing on an old truck, we find it falls off" ~ me
Some TF series details & TF heater pics