Belt guidance

I have a gen 2 hemi, that I used all the pulley's off a 383 with the Saginaw pump. Everybody called for a 39 1/2" pump belt, but I had to get a 44" to get it right. Local auto stores are phasing out belts, because the serpentine belt is the now in belt. I used a string around the pulley's to get me the right size. Anybody interested in a 39 1/2" belt never used. Just kidding.