Bill,
I went out and confirmed that my radiator support bracket was 3-1/2" away from the front crossmember rivet to the rear radiator bracket rivet, the exact same dimension that you show in your picture. This is on my '55 truck that is mostly complete. I will know tomorrow where I am at on my '58 frame with the Monte front clip. It is at a different location at the school where I work. I need to get some pictures posted of my situation, and will try to work on that tonight still. My radiator support bracket is attached with rivets exactly 5" apart on center. The core support was attached at the center of the adjustment, or at 2-1/2" between the rivets of the radiator support brackets. You could see the wear and rub marks made by the rubber grommet that were between the core support and radiator support brackets. Thanks again for your help.
Ed
