I have run into this problem before. (I bought a set of 4 1/2 wheels from a fabo member who said they were 5 1/2...) Problem is establishing if a wheel is a 5 1/2 or a 4 1/2... My understanding is that the 4 1/2 were standard including on V8 cars. I am pretty sure not all V8 cars came with the 5 1/2 wheels. My guess is you may have the 4 1/2 wheels. The 5 1/2 wheels came on performance cars like the Swinger 340, GTS, and Formula S cars A body cars in 68-69.
