Originally Posted by MidnightBlueGT
No but the new gear ratio will offset your speedometer and make your mileage be inaccurate. There are other ways but for the $ getting a tuner is worth it but no you dont need one if your fine with it.
Id go tuner first then buy gears after
+1 my speedo was WAY off after I had my 4.10s installed. Tuner brought it all together, worth getting before gears. I do alot of highway driving and my 4.10s do just fine on the highway. Personal preference, but I dont think i would have been satisfied with 3.73, but no plans on FI for me.