adapting the 3-Finger clutch

[modelajunky]

Does anyone know where I can get the specs (radius specifically) on the location of mounting bolt holes for the 3-finger pressure plate to be adapted to a cut down A flywheel? I am having my friendly machine shop cut down the flywheel as per Les Andrews' book, but the six bolt attachment holes need to be accurately drilled on the new surface. I have a Speedway 9-inch PPlate, but they don't know their own specs. Even worse, they referred me to Rabco, their supplier, and they don't know the specs either. My machinist wants to be as accurate as possible, to avoid my shaking it to pieces later. So, laying it down and marking with a Sharpie isn't going to cut it (that's what Rabco suggested).
Thank You for any help you can give me. - Bob

 

[James Rogers]

It is vitally important you get the diameter of the bolts and spacing correct. If it is the same plate I use (also from rabco) the diameter of the bolt holes is 10 3/8" The radius is 5.1875. The spacing is 32 degrees with 120 degrees between individual holes. A competent machinest could find the spacing once the plate is centered. I hope you intend to have it balanced after the work. I could have sold you one probably cheaper than what you will pay your guy.