I have an '07 GT and I want to put 3.73's in over my stock 3.31. I am probably going to buy from AmericanMuscle.com but I'm not sure if I need both kits they have listed. I'm assuming I have to get the $75 bearing kit, but there is an "installation kit" also for $35. Do I need both? My car has about 16,500 miles if that has any weight on whether it needs bearings or not.

I also read other postings where people were talking about recalibrating the speedometer. Is that necessary?

Any help is appreciated. I don't want to waste money buying things if I don't need them. Does anyone have an approx. install cost too?

 

I don't know if the bearing kit is required...I don't think it is but not sure. The install kit is.

But - as you probably know this is not a do it yourself mod. You will need to find a competent shop, with Ford 8.8 rear end experience. Talk to them, you can probably order thru them or at the least they will tell you what is needed.

Yes - recalibrating the speedo is required because your rear tires will be rotating at a faster rate per the same engine RPM. You can do this yourself with a tuner like the XCal2 or equivalent. If not your speedo will be off.

Install cost varies by local but minewas $550 for labor, gears, kit and fluids.

 

Even if I knew how to do it properly I wouldn't. I'm way too lazy to do work that technical. I'm guessing if it is a reputable shop they will have the necessary handheld to reprogram for the gear difference. I'll make a call tomorrow and find out what it'll cost. My only concern is buying the two kits which puts me over budget. If it is necessary then I'll do it obviously. I just need that information to order.

I hope being that the "Master Bearing Kit" on AM.com is Motive brand that it won't being a sacrifice of quality. It isn't exactly cheap anyway.

Thanks for the info though. $550 sounds pretty good for the whole package. I keep forgetting that oil needs to go back in.