What Speedo Gear to Use

apparently 3.73 won't give you a good advantage on an auto. 4.10 is what you want (or so ive read)

First of all, you would want the 21 tooth with 3.73 gears.

Additionally, like was mentioned already, you REALLY should go with the 4.10's and the 23 tooth speedo gear. While you are at it, might as well throw in the Posi unit or T-Lok. It will save you money in the end should you ever decide you yearn for both tires to spin. Get the gears, speedo, and T-Lok from GEFRacing, and then order the install kit - 1979-04 Rear End Master Bearing Kit (1979-04 7.5" ) YK-F75 from http://50resto.com/

Here is the part you want:

http://secure.50resto.com/product1.cfm?SID=1&Product_ID=1904&Category_ID=652

I put the 4.10's on my 98 auto and it is nothing short of amazing. The transformation is unreal, and I launch so much faster now. Infact, I can chirp BOTH tires when going into second gear (TransGo shift kit gets some credit here as well)!

A note about the speedo though. With the 23 tooth gear, your speedometer will be off by 5 mph when you are going 65 mph, your speedo will read 60 I think? You will want to take apart your gauge pod, pull the face plate off, and remove the speedo needle and the stop post located under 0 mph. Put the speedo needle back on the post just a bit, enough for it to stick. Get a friend to pace you at 65 - 70 mph, which ever you agree upon, and when he hits that speed, have him hit his flashers or something, then engage your cruise control. It's a good idea to have a passenger along for the ride to watch the road for you while you screw around with putting the needle back on the post at the correct mph. Put the needle on just enough to make it stick, then pull over and put the needle back on securely. Don't press it on while you are still driving around as you can damage the speedo mechanism in the pod.

Your other options are to find one of those roadside "you are going this fast" radar displays, or find a police speedtrap and ask them for some assistance. I did all three over the course of a week or so, just to make sure.

Again, the 23 tooth gear will get you the closest to the correct speed, not exactly. The 4.10's are the way to go, or else you are just wasting money on 3.73's. Get the T-Lok, trust me! And get that install kit I linked you to, your mechanic will love you for that! Also, pick up some rear end axle seals and have those replaced if you haven't done so already as the mechanic will have to pop the axles out anyway to intall the the stuff.

If you want to save some time and money as well, go pick up three qts. of Mobile synthetic gear oil, and the gear oil friction modifier - only use the Ford stuff!

After 500 miles of driving or so, take the car back and have them inpsect the gears to make sure there is no unusual wear going on, and to replace the synthetic oil and modifier. The rear end should be good for 30k miles after that, then all you do is replace the oil and modifier again at that time.

The only problem with the 23 tooth gear is that your odometer will not be correct. Use math to figure out your real reading based on the 65 mph is really 60 mph (I think - or its the other way around), but remember if you are a stickler for getting oil changed every 5K miles, then use the odometer as your engine is really turning a bit faster to get to the same speed as before, thereby putting in more miles past the actual 5K mile mark. Does that make sense?

Let us know how it goes!

i have heard the rumors that the vert will be apearing in 06, along with the rumored Cobra... (interesting to see how they will change the fascia, hood, and spoiler this time around, no?)

New MotorTrend Says Base and GT coupe out this fall. Base and GT Vert. Out in the spring of '05, Cobra not out until 07