I had a 1990 2500 pickup, with 6 lugs. It was a 350/ automatic 4X4. I had a "condenserator" installed. It was an exhaust gas, or crankcase gas filter, recycler. Im not exactly sure how it worked, but my mileage went up from 13 to 17, and the throttle response and power seemed to increase. I now have a 2000 k2500 with the 5.7. I sure would be interested in getting another one. Anyone know anything about it?