Has anybody purchased an exhaust from Diesel Pro. They have an add in the latest issue on page 13. They advetise a four inch system for $440 aluminized and $575 for 304 Stainless. Wondering if anybody has installed and seen the quality and fit. Sales rep tells me stainless is a lifetime guarantee while the aluminzed was a 10yr. system, but I sensed some hesitation on his part concerning the ten year warrantee. I have noticed other manufactures only offer a 1 year with the aluminzed. Any other input would be helpfull, noise, emission testing, power gains etc. Truck really only needs a tail and muffler but that is going to cost $380 in parts, factory system is only 4 yrs old. Thanks