They fit well. 1994 k2500 350tbi. I was able to bring both up. They sound good and performance has improved. I don't know fuel consumption yet. Now for the bad. When you put it on, make sure that the truck is running for a long time so that the paint burns off completely. smoke something nasty I thought I had a fire under the hood. Second, the bolts they use to mount the exhaust pipe are crap. I installed them and after half a day the bolts came loose and I lost my left exhaust pipe. After…