I need someone who has a 4.2 and a tach to take 3rd gear all the way up to 5200RPM and tell me what speed your going cuz id like to know what speed i have to go to get all the horsepower out of the 4.2 that i can get. Someone please tell me thanks alot

 

what year truck? do you have digital trip meter? what rear end (ratio)?
Brian A

 

2001
it does have a digatil trip meter and it has 3.55 rear ends

 

[updated:LAST EDITED ON 01-Jul-02 AT 07:40 PM (EST)]Some info for you.....copied and pasted from a post I did several months back. You have a tach. and didn't even know it!!!

Brian A

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....using the digital odometer/trip meter as a digital "test" meter on my 2000 F-150. Simply press the button on the odometer IN and hold IN prior to turning the key to RUN postition. Turn key to RUN and continue to hold button IN. After a few seconds, the odometer will switch to TEST mode. Start the truck and the odometer remains in test mode until turning engine off. Press the button and release to scroll through test modes. This mode allows you to test Gauge Indicator operation, Dash lamps, provides a DIGITAL TACH, etc.

For the record (if you have 255/70 16 tires) in O/D you have 32 RPM per mph. Example 70 mph x 32 rpm = 2240 RPM.