With an AOD...??
 

Which gears would you go with? With an AOD? How bad on the is the rpm's at highway speeds? Anyone try the new 3.90's?

I like...
 

I like my 3.73's. brought life to my stang.

How is it at highways speeds?

3.73s

Highway acceleration is much, much better. About 2450 RPMs at 65-70.

Thanks,
DoranW

3.90's
 

I have been looking at the 3.90's also I have 3.27's from a aod 86 gt right now but will be making the same decision soon.I will probally go with 4.10's because my car see's the track more than the street.

I would go with the 3.73 as long as your tranny holds up, after a few races my over drive started slipping but it had 93,000 miles on it.The gears really made a performance differance.Real easy to smoke the tires. I changed to a c4 now the gears are to low for the highway about 3000rpm at 65-70mph.

It wasn't on the list, but my 4.30's work great with the AOD...'course mine doesn't see much, if any, street duty any more. I'm going to get my plates again this summer though.

I've got the wide ratio gearset in my AOD and that with the 4.30's have given me solid 1.50 60' times with a few down into the 1.4's. With the new motor, should see something around 1.45 60'.

With the 2.40 first gear (stock), give it all the gear you can along with all the converter you can stand.

I have 3.73's in my car and they are nice, but there is just not enough gear to get me off the line. I think you should go with the 4.10's, you will love the way your car comes off the line with them. Hope this helps.

-Billy

4.10's without question. I had them both. The 3.73s lasted about 1.5 year, then went 4.10. MAJOR improvement. I also eliminated lock up converter, and it still not bad on the highway. Sure, it wouldnt be my first choice to drive cross country, but I take it on 2-3 hour trips on the highway with no problems

I can cruise 70 mph around 2500 RPM

From all the other topics about this issue i have found that 3.73's are best for manual's and 4.10's are best for AOD. THese are street car recommendations by the way. I dont think i have ever seen someone here with 3.90's

Later,
Nick

They are the new gears from Motive Gear. They some other new gear ratio's but I have forgot them.

I am very happy with my 3.55s, would have gone to 3.73s but got a sweet deal ($20 - 500 miles) on the 3.55s out of a new cobra. Runs about 2500 rpm at 85 mph on the freeway in overdrive