Well, my gears are in along with my tuner, was going to install this weekend but will wait to make sure the 4.10:1 are not too much for the sc I'm adding..Any one running a KB or even you 03-Cobra guys running 4.10s let me know how they work with the roots!

 

just install it and love it. 4.10's are a little steep for me but you'll really like it in all likelihood.

 

Why too much gear for you? I have 373 in our 99, feels ok.

 

because I don't have a motor that needs to sit at higher rpm to make power. My motors all make their peak power at moderate RPM's so I don't need to climb to the top of the tach to get going.

My rule of thumb is, if your power (tq) starts peaking at 4400, then 3.73's are plenty. If you go to 5500 before the tq peaks, then 4.10's. If you peak at 6500, then 4.30's or 4.56. If you're like me and like torque monsters that develop peak twist at 3500 and peak hp before 5500, then 3.55's are plenty if even a little much.

Use a gear that gets you into your power band quickly but doesn't shorten the usefulness of your RPM window too much. If you redline at 6K, then using 4.10's is a little much.

 

I agree, that's why I feel the 410s may be too much. I have a set of 355s from my 93 5.0L. Are you running an sc?

 

4.10s and a KB on street tires = no traction at WOT in 1st and 2nd. When I have my M/T DRs on it is a hell of a ride though!! Heres a short vid to give you a little idea.... http://videos.streetfire.net/video/1...3B0C4CC939.htm I have a set of 3.55s waiting to be installed now. I think they will make the car a little better on the street tires.

 

I think I'll wait, try the stock gears and see how it handles the added power. May have a set of 410s to return. I ordered them a long time ago, before the sc was even a thought. I do still have some 355 with about 2k on them, so if all fails I'll put those in. Nice setup btw, car seems real fast from the video.

 

I've driven dozens of BIG hp cars with everything from 4.56 to 3.08 gears. For your average 360rwhp blower car I like 3.55's. They're just at the limit of traction pretty much all the time but you get better 5th gear hill climb and passing with 3.55s than 3.27's without blowing too much gas milage.

3.73's have always been tire spinners on blower cars for me. They're just too aggressive for street tires with all that power. Roots/twin screw types add lots of low end grunt so, if you had something like a centri or a turbo, then 3.73's aren't too bad a choice. 4.10's are reserved for 4v and other high winding motors in my book.

All in all, try your 3.27's. You'll be pretty happy with the power from that KB. If that's not enough, then your 3.55's will be a nice small bump. 4.10's will be a dramatic change. I think you'd like the 4.10's most of the time but you'll eat tires if you're young and ... energetic.