Thanks for the info.  All pulleys are the same width except the inner crankshaft pulley.  I didn't consider belt width.

Stock there were a couple different belt widths, depending on application. Mixing pulley widths would be a problem, especially with aftermarket pulleys. Old belts can get hard, or glazed. Many brackets require some shimming to get the alignment right. Any mismatch here could cause slipping.

I don't know about trucks, but generally the one belt is crank-gen-water pump. The p/s is crank-pump.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

I have a problem with the fan belts 0n my F-100 slipping.  Don't know if I have them  routed correctly.  I have added a double pulley at the crankshaft,   Power steering {brackets from John Mummwert












































I have a belt slippage problem on my 55 F-100.  I am not sure how to route the belts.  I have added a crankshaft double pulley giving a total of three grooves. Power steering brackets (by John Mummert)  AC and alternator  bracket from Vintage air w/Double pulley.  G.M one wire alternator  w/double pulley.









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