Michael, Aftermarket parts for your Cat engine ahead will not save you money but cost you money.
You have a very big cost in your engine and engine is built and tested by Caterpillar using Caterpillar
parts. I have run into many failures because a aftermarket part failed. It is very hard with motorhome
owners going a different direction other than buying correct cat parts. The biggest one I find is non
use or aftermarket fuel filters in electronic cat engines ( price out a set of injectors for C-12 engine )
This is the end result of failure to use correct cat 2 micron fuel filters. Aftermarket sensors, engine
Thermostat non-cat, adding power chips to engine to name a few. I guess after reading many post
It's very hard to give out correct advice on caterpillar maintance when cost comes into play.
Dave Atherton retired Cat mechanic