View Full Version : 4.10s

12-02-2003, 01:59 PM
Does anyone else have 4.10s on there AOD sc? Im getting some pretty doon and i was wondering about what rpm ill be doing in overdrive at 70?


Rob Noth
12-02-2003, 02:50 PM
I think there is a calculator on the SCCOA site somewhere for figuring that out. But roughly it would be (current RPM) * 4.10/3.27.

Another perspective - if you're interested in racing then 4.10's would be a bad choice, since it means you'll run out of third (D) before the end of the track and have to do a full throttle shift into OD, if your tranny would even let you do that. Not a good idea. I have 3.55's and I think that's as tall a gear as I would want with the AOD ratios. A lot of people also seem to be happy with 3.73's.

Plus with 4.10's, your driveshaft speed will be about 25% higher. Stock steel driveshafts aren't very well balanced, and it will be much more noticible at freeway speeds.

12-02-2003, 03:24 PM
I'm putting 4.10's in my car..With my mustang aod (same gearing as yours) 26 inch tall tires, Id pass the traps right around 5500....However I have the wide ratio kit in my new car and am unsure what will be going on..I could always go with a taller tire:O)

David Neibert
12-02-2003, 03:40 PM
After trying the 4.10s for a couple months this past summer I decided they are a bit too much gear for me, and went back to the 3.73s I had before. Mainly because at the time the higher rpms were making my cooling problems worse.

With 3.73s and a 2700 stall non locking converter that always slips 200-300 rpms, I've gotten used to cruising at 2700-2800 rpms at 75 mph. With the stock locking converter and 255-45-17 tires the rpms were around 2500.

With 4.10s and the non locking converter and same tires the rpms were around 3000 at 75 mph. They worked good for me on the track and even with the slippy converter and 26" tires I was clearing the traps at a little more or less than 6000 rpms in 3rd doing 110 mph.

They will be okay, but I think you would be much happier with the 3.73s


12-02-2003, 05:29 PM
Thanks for the Input guys.. Hey Dave when you ran the 4.10 gearing did you run down the track? Did you notice a difference between the two gears?

P.S. Your car is my background on my computer :D Very very nice.

12-02-2003, 06:46 PM
Whatever you do rebuild your diferential while your back there:O)

David Neibert
12-02-2003, 09:51 PM
Hey Dave when you ran the 4.10 gearing did you run down the track? Did you notice a difference between the two gears?

Yes, they were about 1 tenth and 2 mph quicker than the last time I raced with the 3.73s. Then again my engine likes high rpms and yours may not. Chris Wise ran with my 3.73s and his times and mph were just about the same as with the 4.10s.