[rick500]

My 5.3 recently passed 100K (2010 Silverado 1500 LT) so decided to change both belts. Went to autoparts store and of course they use computer to look up PN's They had a couple of selections but been using GATES for decades so picked up AC and main belt.

Noticed different 'PK' numbers on the main belt. looks like the replacement gates 6PK2374 was a bit bigger (OC) than original (6PK2370). So translated the numbers and sure enough, new belts were slightly larger. Fitments no problem with tensioners but just curious if this was belt manufure(s) best match, a GM change or? Any thoughts?
Thanks, Rick

 

[country1911]

The smaller belt is for a different amp alternator. Most auto parts stores default to the bigger belt ao it is easier to put on and will work with all alternator sizes... i have to specifically ask for the 105 amp alternator belt to get the right one. Use your RPO codes in the glovebox to determine your alternator size if you dont know it.

 

[rick500]

That makes sense, didn't consider alternator size. Plus it was easier to install. Thanks