It was basically the same engine with a few differences. I think, but not sure, the Pontiac was 4 barrel carbed and the GMC 2 barrel.

"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.