A simpler approach would be to machine the face of the pump pulley back a little, or press it back toward the housing if there's room to do that. When I converted one of those pumps to a double belt arrangement, I machined the cast iron sheave away altogether, leaving just the hub with the 4 bolt holes, and used a sheet metal 2-groove pulley for a Ford 302 V8. I used a 2-groove balancer for a 250 Chevy six to run the second belt for an air conditioner compressor and an alternator. Worked great!

It would also be a good idea to check on the condition of the motor mounts- - -two back at the bell housing, and one under the middle of the timing gear plate at the front. It's possible that the engine has shifted forward due to worn or broken mounts.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
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