Sometimes from the factory they put some kind of anti-tampering device. Mostly what I've seen is a "torque lock" where they squirt stuff out of a tube and lay it over the fastener. If the fastener is tampered with, the torque lock will show it, either by being missing or broken. Thus the technician can rightly so deny any warranty claim.

For the most part, they would put the stuff on all the fasteners on a given component, so if it "somehow" degrades (which it WON'T) they can look at the other fasteners to see.

I have seen it used on some satelite tracking systems in highway tractors, and some drivers disconnect their satelite recievers to "go offline." Those drivers didn't have a job after that.

Edit: Anyway, if you're not afraid of losing your warranty, I'd say go for the propane injection. I have seen a dually Dodge with a Cummins light up it's duals in second gear.