As far as I'm concerned TST is a great operation. . I'm new to diesels but not mechanics. . When I called TST and spoke to Mark he was patient. . knew what he was talking about. . and did'nt seem to exaggerate. . The thing that impressed me the most was that he took time to answer all my questions. . and I called him 3 or 4 times. . Now after the instalation and fine tuning, I realized everything he told me was correct. . there were no suprises or let downs, if you know what I mean. . This patientence and truthfulness is a form of confindence I have in these people that I'm willing to recomend them to other people and believe me I don't do this often. . The man knows what hes talking about and is willing to help, even after purchase, this is a class operation and of course my opinion. . I would and have bought from them agian. . if you have any more questions you can also e-mail me. . Good luck and by all means have fun. . lifes to short. .