I have a problem. If I leave the rear window of my 85 K5 open which I like to do on nice days, I get a lot of exhaust fumes inside the cab. I was planning on redoing my system when it finnaly rotted out and I'm close enough now. Only thing to keep in mind, I drive in sub-zero weather with lots of snow about 4 to 5 months a year. On the other hand we don't have emissions testing here and so if my old system should fall off just before I take it in the mechanics will put on what ever I want and omit any unnessesary parts.