We all know that the chip shut off fuel at 120 MPH due to engineers worried about front end lift and the rating of the tires. I was just re-reading the August 1987 Motor Trend Article and they asked the same question. Before chip mod I had mine up to 120 and it fell flat...after chip mod went up to 147 according to scan master before I let off...so what is top speed on a STOCK GN...the 147 was with adjustable waste gate...