Need help please

[66Submarine]

FWIW, a lot of guys (almost all of them IME) run the later 9/16" stud wheels on the trucks with the 1/2" studs; I don't think a lot of people even seem to notice it unless they try to put '70 or earlier wheels on a later truck. The conical-seat wheels on my '65 C30 SRW even worked fine with the 1/2" stuff. The dually wheels are also truly hub-centric, and with the flat lug nuts I don't really see it as a problem unless you let the lug nuts get loose (which would obviously be a problem anyway). Some good washers would probably be a nice idea, though.