I got this kit off ebay years back that is a propane injection system for 454's. It was touted as adding extra power and was meant for RV's. It has two small injectors that are triggered by a vacuum sensing switch (staged, you can select power levels). It looks similar to a nitrous setup but the delivery rates are probably less. I know propane acts as a catalyst on diesel fuel the way nitrous works on gasoline. I am considering hooking this up to a nitrous bottle rather than a propane bottle. If nitrous helps to achieve a more complete combustion, does this = cleaner emissions? If so, it might be beneficial to turn this on during emission testing. Any thoughts?