According to the Chevrolet GMC trucks 1954 maintenance manual from GMC of Canada, a 1500 is a 2-ton equal to a US 6000 series. It would have either a 137", 161" or 179" wheel base.
The US equvilent would be a 6100, 6400 or 6500, respectively.
"It's just a phase. He'll grow out of it." Mama, 1964