If the rear is from a Nova its either a 4-lug or a 5 x 4.75. Five lugs on a 4.75 inch circle which was the common Chevy car pattern for many years.

5 x 5, and now 5 x 100 (metric) are other common Chevy patterns, neither ever used on a Nova.

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...