I needed someone to install my turbo and T-4 kit on my truck, after some word of mouth I decided to give Underground Diesel a try. They responded quickly via email with an estimate of 6-7 hours, this sounded reasonable so I dropped my truck off on a Monday. Unfortunately there was some resistance during the install and it took over a week. The guys there are men of their word and stuck to the original quote even though it took much longer, the end result was a very clean install and a great running truck. I would recommend them for sure, the only reason I give them 4/5 stars is the length of install compared to the original quote of two days maximum.