Okay I've done some reading on the posts here about people putting 4.10 gears in their stangs and it seems to be a pretty popular upgrade. I mentioned that I wanted to do this mod to my uncle, who is an old school mechanic, and he seems to think that it's going to mess things up unless I replace my whole computer or have it flashed and completely reprogrammed. He started talking about messed up fuel injection, rev limiter, & shift points among other things. I told him that the shift points should be the same and it shouldn't make a different on the rev limiter nor fuel injection and that. From what I've read, the only thing you should have to do is either change the setting in the computer for the new gears to make the spedo accurate or change the spedo gears in the tranny. From some of you that have done this, was the correction for the spedo the only thing you had to do after installing the gears? Also, what kind of fuel mileage differences did you notice, in town and out. Thanks for the help.

 

You just need to get a speedcal from dallas or brothers. Also, you need a bearing kit for the pinion, since the old one is virtually impossible to get off without ruining it. Measure the pinion with a digital venier caliper and do the same with the ring. You need to work off those numbers to match your new gears. It will be quite easy if you do that. Did mine without them and it only took about 3 hours total. There are a few good gear write ups that you can google. You'll need to torque down the new cruch collar to specific amount. Ohh, you'll need to pry it your ABS gear on the inside of your axles wher your wheels are in order to get the c-clip out of the diff.

 

All you will need to do is get the spedometer recalibrated. Other than that, you'll love them.
I did my gears myself as well, and if you are going to do yours yourself, I can give you the link to a great set of instructions.

 

give us the link please

 

Me and my buddy install my 4:10s a few days ago.I went with the spedo gear,the speedisstill off some but it is pretty damn close (about 2-5 mph off),and it cost way less then geting it recalibrated at a dealer.you lose a few mpg on highway,in town its about the same if you dont floor it all the time,but man it is worth it.it give your car such a big kick.
as 97targa said you will need a new bearing for the pinion,it cost around 20 bucks,andyou will have to get that press on.And correction of the speed is the only thing you will have to do.

____________________________________
98 Mustang Gt
o/r h-pipe,flows w/ dumps,mac timing adjuster,
4:10 gears,steeda short thorw,king cobra clutch,
scremming demon coil packs,10mm race wires,
k&n cai,75mm tb,upper plenum,bbk pulleys,
coming soon nos and full pi swap!!!

 

http://www.corral.net/tech/drivetrain/gears.html

Here is a link for a guide if you are going to do it yourself.

____________________________________
98 Mustang Gt
o/r h-pipe,flows w/ dumps,mac timing adjuster,
4:10 gears,steeda short thorw,king cobra clutch,
scremming demon coil packs,10mm race wires,
k&n cai,75mm tb,upper plenum,bbk pulleys,
coming soon nos and full pi swap!!!

 

Here's the link to the instructions I used:
http://www.superstallions.com/tech/d...ars/gears.html
Worked great for me. You will need to get a machine shop to pull the old pinion and carrier bearings and press the new ones on. Other than that, if you have all the tools, it is an easy job.

 

When you guys did you upgrades, did you put on a tranny cooler or bigger pan or anything like that?

 

Should ditch the speedo gear and buy a DM speedcal.. It will be dead on and no needing to go to the dealer for anything..

 

scfd524, just wanted to give you props for doing research on your own first before starting a whole new thread about 4.10 gears!! Good job. This is very rare! haha.