Rod bearings

FlHermit · July 5

2000 Express 3500 5.7 I'm confused on the rod bearings. All are marked GM A-100 on one end. But on the other end some are marked A926 and some are marked A921? What am I missing

newdude · July 6

17 hours ago, FlHermit said:

2000 Express 3500 5.7 I'm confused on the rod bearings. All are marked GM A-100 on one end. But on the other end some are marked A926 and some are marked A921? What am I missing

Going off pictures on eBay of the bearing p/n 10120990 (which is the current main bearing #), the ones with the "GM" look to be GM bearings. The ones with the A921 and A926 are likely aftermarket bearings, so I'd say someone might have been in that engine before.

Here's a picture of one out of a fairly new box and its stampings:

Here's the stampings from some older stock:

If you look at the second bearing half from the left its stamped like your first picture.

Here's some evidence of the "GM A-100" on factory bearings in an older engine. The bottom numbers are date code so your "GM A-100 8-01" is a factory GM standard bearing, August 2001.

What rod bearings do i have GM SBC 350 | Hot Rod Forum (hotrodders.com)