C20's are all 8-lug. The 3/4-ton trucks that have six lugs are all different models.

You might want to do some part number checking. The one year I've researched was a disk brake model, but on it it seems all the front suspension part numbers were the same on both 3/4- and 1-ton trucks.

All the earlier 1-tons I've seen converted to IFS using this suspension used a 3/4-ton instead of a 1-ton.

1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...