Yes, that is the gear ratio. It was an option in GMCs from the mid '50s to mid '60s. Also Blazers from the '70s area have 6 lugs and close enough width.

One member here just used a Nissan 6 lug rear.

"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.