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Jeff Chambers · 10-27-2005, 07:14 AM

If its an auto, the stock gears are most likely a 3.30:1 and if its a stick its 3.55:1 gears. If its a V6, then it has 3.30:1 gears whether its an auto or stick. If you do change gears, your speedo & odometer will be off unless you re-program the computer for the gear change or use an add-on box like the SpeedCal.

If its an auto, go with a 3.90 or 4.10, if its a stick go with the 4.10. The 5R55 automatic doesn't need quite the help like the AOD/AODE transmissions did, that'w why I think the 3.90 is an acceptable alternative for the 5R55.

10-27-2005, 07:14 AM	#2
Jeff Chambers Moderator Join Date: Aug 2000 Location: Milan, OH Posts: 2,699	Re: stang 05 rear end If its an auto, the stock gears are most likely a 3.30:1 and if its a stick its 3.55:1 gears. If its a V6, then it has 3.30:1 gears whether its an auto or stick. If you do change gears, your speedo & odometer will be off unless you re-program the computer for the gear change or use an add-on box like the SpeedCal. If its an auto, go with a 3.90 or 4.10, if its a stick go with the 4.10. The 5R55 automatic doesn't need quite the help like the AOD/AODE transmissions did, that'w why I think the 3.90 is an acceptable alternative for the 5R55. __________________ Jeff Chambers 1990 Mustang GT 10.032 Seconds / 137.5 MPH 14-time Street Warrior World Record Setter CRT Performance 2001 Tropic Green Mustang GT - 12.181 / 113.2 MPH 2002 Ford F-250 Crew Cab 7.3l Power Stroke - 17.41@77.2 "There's nothing boring about a small block automatic shifting gears at 9400 rpm!"