I am getting tired of having high EGT's and not being able to blow my head gasket (yes, you read that right). I would like to get myself a water injection system. I tow a fair bit, so I plan on running a larger tank on the bed for added capacity.

Just looking quickly, I found THIS.

I like the variable rate, boost referenced controller. The question is, could I piece my own together for cheaper? If so, where should I look for parts? What all parts do I need?

 

There's a mention of higher-octane fuel in that description, so it might be calibrated for lower manifold pressures.