This is the pulley I designed around, and it's fairly common. I've also seen it on '92 & '93 gas trucks, and others. The ACDelco/Gates number for the pulley ALONE might be
38006; Dayco might be 38007. The spacer is not used for tensioners, but it's required for idlers and for this mod. Some bolts are 10mmx1.5 with a 13mm head, but others are 12mmx1.75 with a 15mm head & a matching spacer.
Turns out this bolt is actually 12mm. An earlier one I checked was 10mm, and I didn't realize this one was different when I added that text.
![idler.jpg This is the pulley I designed around, and it's fairly common. I've also seen it on '92 & '93 gas trucks, and others. The ACDelco/Gates number for the pulley ALONE might be [url=https://www.amazon.com/dp/B000C9OLPY]38006[/url]; Dayco might be 38007. The spacer is not used for tensioners, but it's required for idlers and for this mod. Some bolts are 10mmx1.5 with a 13mm head, but others are 12mmx1.75 with a 15mm head & a matching spacer.
Turns out this bolt is actually 12mm. An earlier one I checked was 10mm, and I didn't realize this one was different when I added that text.](https://www.supermotors.net/getfile/947195/fullsize/idler.jpg)