Firestone number one. Only do you know when you buy a Firestone kit you get what you pay for nothing but quality. Everything fits precise Firestone thought of everything for you. I put mine in in 30 minutes from start to finish. I was so impressed, that I bought another kit for a different truck the next day.
Installing was easy. We mounted the unit to a sheet of aluminum that we cut to fit under the back seat and behind the flat load floor on the right side. We kept the unit loose under the back of the seat in case of need to get to it to work on it. The air lines were run through a small hole drilled into the back of the cab and then sealed around it. The unit works very well and the air compressor noise in the cab is very tolerable since you only hear it when you inflate or deflate the bags.