What speedo gear do I need?

[jeffcobra]

I just got the car back from the shop. It now has 3.73's in it. What speedo gear do I need. I was thinking 23 teeth but want to check with you guys.
I'm also swapping out the tires for some 245/40 R17 track day tires I have. Those are going to be a little shorter than the stock tires. What do you guys think?

[cobrabitn]

The tires will work fine but why not 275's with some terminator wheels? To get the best result, you should change the tranny gear and use a 21 tooth gear.

[jeffcobra]

275's would be the way to go but I already had a set of 245 Kumho Ecsta XS (http://www.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=Ecsta+XS&partnum=74WR7EXS&vehicleSearch=false&fromCompare1=yes) tires that have zero miles on them. They were ment for another project car but I have decided to step up to 275's on that car so i would like to use the 245's up. They will be a ton better than the all season Hancooks that came on the car when I bought it. The Hancooks were screaming at Summit Point and the car under steered badly.

Here's a video of the Hancooks screaming. It's just a Hyperdrive.
http://www.youtube.com/watch?v=mVE_df1elo4


I don't want to open up the trans so I guess I will just get the 23 tooth gear and see how long it lasts.

[cobrabitn]

Looks like you had a lot of fun! We'll be back at SP in August on the Shenandoah Circuit but I would like to try the main circuit next year.

[jeffcobra]

Has anyone tried this product instead of a gear change?

http://www.americanmuscle.com/ford-speedo-tool-9410.html