Gm 3921923bm single groove pulley ?????

**STEFS** · #1 03-11-2018, 04:29 PM

I have looked this part number and every thing I see is a double groove...... not single ???? Any help on this ????? thanks joe

**AMANOCC** · #2 03-11-2018, 07:41 PM

I've seen the second groove machine/cut off plenty of pulleys.

**STEFS** · #3 03-11-2018, 11:16 PM

This is not cut at all

**JRSully** · #4 03-12-2018, 10:54 AM

Post a pic of it, if you have it. I have had one of these for years, same p/n and wondered if it was orig or not. I cannot see Chevy having the same for a single and double groove pulley, but who knows for sure

**STEFS** · #5 03-12-2018, 01:19 PM

Here are some pics As you see it has not been machined thanks joe

**JRSully** · #6 03-15-2018, 11:36 AM

...5291 is the BB double/deep groove pulley p/n

the427king · #7 08-26-2021, 10:43 PM

The early cars had driver pulleys for the power steering cars. Ive never seen a single groove 923 . No way the single groove is a replacement it would have to be the other way around