Truck Forums - Need 350 SB assistance.

Hi all,
New member with a question ,of course. I have a 75 K10 with a 350 that I have pulled with the intention of rebuilding. On pulling it apart I find the attached number and logo on the rod and main bearings. I figured that the 010 means and oversized bearing but the same logo and number is stamped on the bearing caps which didn't make sense to me.

If you turn the crank and use oversize bearings to compensate what does that have to do with the cap? I would think the cap would be unchanged unless someone align bored them.

Does anyone recognize the logo? I want to be sure it's not a part number before I order oversize bearings. I may end up replacing the crank as I have heard of failures on turned cranks but want to be sure I can drop in a stock one without problems but the cap stamp is bothering me.

I don't have the history of this truck. I bought it from a kid who didn't know much about it. The block is a 4 bolt and according to the casting numbers it's a cast crank, lightweight (crack prone) heads. It’s been rebuilt before. Felpro gaskets and "20" on the pistons.

I also had broken rings on the 2 front most cylinders. They were the number 2 rings. Does anyone know why those would break before the number ones? All I can think of is improper install.

The left rear piston is all beat up from a foreign object. The cylinders are in surprisingly good shape after all of that.

Any info would be appreciated.

Thanks

Mike