I've decided to go with 3.90s since I'm undecided between 3.73s and 4.10s. Well my question is how bad do these gears throw off your speedo? Other than the obvious innacurate speed reading are their any other negative effects? I ask because I can't really afford that speedo-calibration thing right now. I decided on the 3.90s since soem kind of FI(nitrous) is in my future sometime before I die[&:]

 

you'll put more miles on your car.

 

just get a speed cal if your a 5 speed, if your an auto, then you need to recalibrate it causeeverything will be thrown off

btw its a 100 rpms and like .3 mpg diff between 3.90s and 4.10s, and they arent made by ford, just saying[8D]

 

Well Christmas is around the corner. I'll probably end up going with the 4.10s now that I think about it. I barely drive on the highway anyway. Quick question though. I was looking on americanmuscle for the gear/tuning kits and was wondering which one is better, the SCT or Diablosport?

 

I have a diablosport... but SCT seems to get the rave revues... so just research it, and go with what you like better... IMHO either one will get the job done!

 

Find out what the goods shops around you use for tuning.

 

it is a matter of opinion i think... but i have had both tuners and one gives better numbers on the dyno but i cant tell on the streets a noticable difference