This AC Idler was used in later-produced 67 289 Select-Aire Mustangs and was often installed as a Service Bulletin "fix" for AC Belt deflection/rattle while using the AC at engine idle.
2- bolts are listed in the assembly manuals as 370807-S2 & 377379-S2.
Jim has them listed as available for 1967 use as:
370807-S2 2 FF108 5/16-18X4 1/8HH,PLACE,7/8THD L,1/2HEX BOLT,HEX,SELF LOCKING,PLACE 1 AIR COND IDLER PULLEY-WATER PUMP,289
377379-S2 2 FF040 3/8-16X1 1/4HH,REC,FLNG 3/4,SERR,9/16HEX BOLT,HEX,REC,FLANGE,SERRATED 4 AIR COND COMPRESSOR MTG BRACKET,FXD-COMPRESSOR,200 I6
377379-S2 2 FF040 3/8-16X1 1/4HH,REC,FLNG 3/4,SERR,9/16HEX BOLT,HEX,REC,FLANGE,SERRATED 2 AIR COND COMPRESSOR MTG BRACKET,FXD-COMPRESSOR,289
377379-S2 2 FF040 3/8-16X1 1/4HH,REC,FLNG 3/4,SERR,9/16HEX BOLT,HEX,REC,FLANGE,SERRATED 1 AIR COND PULLY,FIXED-FIXED BRACKET,289
AMK sells the latter of the two for the "OTHER" listings noted above but AMK does not seem to have one of those 4 1/8" lock speacial locking 5/16" bolts.
Does anyone else know how to find such an animal new? My old one is pretty much destroyed and it seems most "EARLY" cars wouldn't typically use them.
Last resort would be to manufacture my own but not what I was hoping to do.