OK, I have had my ne H. O. 6 speed for about 4 months and I'm ready. I sold my 98 4x4 12 valve which had 4 inch straight pipe, more timing, plate forward and boost elbow, guages etc... That truck was past it's waranty so I didn't mind bombing it! This one only has 8,000 on it but I want more power without voiding the waranty. Any help ? Also can anyone help with the procedure for calibrating the speedo? (Bigger Tires) Thanks.