Quote:

Yes it was on a dyno. My last dyno #s were 550 hp at 5300 and 650 torque at 2900. I've made updates since that is why I said 590-600 hp



Your dyno #s and your weight / MPH don't add up. Whether its the result of subsequent parts changes, current state of tune, converter issues (excessive slippage), etc., you're way down on MPH from what 550 HP "should" show in MPH, even at almost 4100#.