Posted: Thu Oct 22, 09 10:59 am
Yeah Andy it is just those little A-Body cars that have the smaller 7/16ths size. Bless them. 
Yes but think of the weight saving
but miles
3 or 4 types
nuts with a profile to seat into a dip at each hole (acorn nuts??)
weird shafted style for alloy wheels which have the profile as well but the shafty bit centres the wheel....if the shafty bit is too long the nut head never bottoms out to clamp the wheel properly
or flat nuts with a profiled washer
or flat nuts with a big thick centreing washer often used on unilug wheels
i too know little about this other than using the wrong ones can cause a wheel to come off.
its a bleedin minefield
picture of wheel centre to the geezer that supplies the nuts may be the go....
Dave