OEM vs Orignal parts

OEM and Orginal Manufactures Parts is the same thing.

Are you asking OEM vs Aftermarket parts?

 

OEM = Original Equipment Manufacturer

 

I don’t know about now with the quality of some aftermarket parts I’ve experienced but names like TRW, Sealed Power, Clevite, and Hastings used to be top notch engine overhaul parts suppliers. With Victor and Fel-pro being the best gasket sets. Most if not all of them were even OEM suppliers to the big 3 diesel manufacturers at one time.

 

It depends what you're replacing. You would have to research each aftermarket company.

If you are replacing rod and main bearings I would get them from Cummins.

If you have a valve cover gasket to replace that you can take four screws off and if it leaks that's okay it'll take a few seconds to fix it.

Especially with bearings and liners and rings No Chinese Hong Kong Phooey.

 

Interstate McBee has always been great for Cummins overhaul kits in the past. They had things in stock for the old NH stuff when Cummins shops didn’t. Cummins down here would even get stuff from them.
I have heard a few negatives from the guys in the vintage truck hobby lately on the quality of a few things that were not an issue in the past.

This made my remember there used to be a custom cam grinder up in Maine who retired and passed on years ago. He’d have good quality marine cams for Cummins and Detriots back then. Totally word of mouth in those days.

 

Cummins has had a plant in china for years. They still build the old NH’s for the construction equipment market over there. You can still get new smallcam crate engines.
Chinese parts even on the new engines assembled in the states is common because of this.
Very hard to tell what is counterfeit or not with the Cummins packaging from china.

Dipaco. Diesel Parts Company is another good source for the injection pump parts. I’ve had great luck with them. They even make a hi output throttle shaft for the PT pump that has a huge hole in it.

 

You are killing me!!!!