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69GMCLonghorn · 11-10-2009, 07:33 PM

I'm guessing the one thing that might be skewing your data is that most speedo's and tach's in these trucks are not 100% accurate (unless you're running an aftermarket tach). In mine, the speedo was off by around 12%. the tach was off by 20%!!!! So find a way to calibrate yoru gauges and try it again.

11-10-2009, 07:33 PM	#4
69GMCLonghorn Registered User Join Date: Dec 2006 Location: Porter Ranch, CA Posts: 978	Re: need help with axle ratio I'm guessing the one thing that might be skewing your data is that most speedo's and tach's in these trucks are not 100% accurate (unless you're running an aftermarket tach). In mine, the speedo was off by around 12%. the tach was off by 20%!!!! So find a way to calibrate yoru gauges and try it again.