Actually the GMC fleet option trucks used the Chevy style instruments.
I take it your dash has the painted panels with the white guage surrounds. You could replace them with the turned metal ones with chrome surrounds from a deluxe cab.

"It's just a phase. He'll grow out of it." Mama, 1964

1956 Chevy 1/2-ton 3100
1953 Chevy 6100 "The Yard dog"
1954 GMC Suburban Now with a new proud owner.