67 L-79 Alternator pulley question?

[kobi67]

I am having problems with what NCRS and the 67 AIM shows as the proper alternator pulley for my L-79, P/S no A/c car. According to the books, it takes a pulley/fan combo assembly # 3875968AW. I have this unit and it is a small diameter pulley and not deep groove. The water pump pulley is deep, I can't understand why I should not have a big diameter deep groove pulley. What am I missing??? Thanks, Kurt

 

[SG4206]

I just measured mine at 3 5/8 " diameter , and it is a deep groove. I thought it was original. Mine is a non power ,non air L -79.

 

[wallyknoch]

Large diameter alternator pullys were almost exclusivly used on high HP solid lifter engine equiped Vettes and Camaros red lined at 6500 RPM`s but naturally almost always exceeded.