Cat C12 performance & mileage upgrades?

This has nothing to do with emissions so I hope it doesn't get deleted.

We bought a 2000 Kenworth with a C12 because we needed a spare truck. For being a 12 litre it does pretty good (way better than that P.O.S Mercedes ever did). I have a new Donaldson M100463 muffler I plan on putting on to help it breath.

I've seen the turbo boost & fuel temp cables on EBay for $65, are they worth the money? Are there any other upgrades a guy can do to these engines?

Like I said, this is a spare truck so it won't see a lot of miles but it would be nice to have decent power & mileage while its on the road.

 

Thanks, I'll check into it. I know horsepower isn't cheap but I don't wanna spend much money since its just a spare truck.