I've got a set of '69 31-spline axles that I'm refurbishing. I need to install longer studs for the disc brake setup. Anyone know the knurl diameter? I can't seem to find anything definitive on-line.
With my 9" from TCP, they supplied 1/2-20 2" studs. Your setup may be different. I am using Wilwood brakes front and rear with Strange axles at the rear as well. TCP does sell 3 inch studs for wheels that have a thicker hub.
Don't hold me to it but for some reason a knurl diameter of 5/8" (.625") comes to mind. Just measure the ID of the holes in the axle flange. The knurl will need to be a few thousandths larger so that they will drive into the flange tightly.
I can't comment on the knurled dia as the Wilwood brakes have threaded in studs. As is usually the case, the answer is it depends. To get a good detailed answer we need a detailed summary of the components being used.