I did a search on this, but didn't find any information. I plan to put a "68 Camaro 10 bolt posi in my '54 3100. I want to use S-10 clamshell wheels (the '98 - 20XX S-10 and Blazer 15" X 7"). I know they are 5 on 4.75" centers, and 4" back spacing, but I think there is an issue with the size of the center opening. Is where one would have to "file" the difference. Either the wheel center or the axle hub? If so, which should be the target?