View Full Version : 411 gearing in my car?

03-10-2005, 05:08 PM
has anyone dropped a new set of gears in there rear axle recently? how much did it cost and would it mess with a 3.8L 87 tranny?

03-10-2005, 07:51 PM
chris1987lx is putting in 3.73's in right now,, see what he says.

03-10-2005, 07:58 PM
Gear changes are a precision job and unless you have the correct tools are better left to a professional.

03-10-2005, 09:50 PM
>>>4.10's<<< are probably a bit too steep for you if you are doing normal every day driving with the car. I have 3.73's and almost wish I put in 3.55's. My gears were shop installed with the speedo gear for $195 for the set and $165 for the install

$360 total and that was at an expensive shop.

03-11-2005, 08:34 AM
Gear changes are a precision job and unless you have the correct tools are better left to a professional.

ive heard the same,, guys up in canton that i know who off road use the dana's. They use terms like "setting up" and "tuning" and "thrust and lash adjustments".

way out of my league for now.

03-11-2005, 11:05 AM
I run 4.10 gears in my car. With AOD it was not to bad and i'm lucky with the track only being a hour and bit away i dont use my car for trips longer then 2 hours.

With T5 its bit better on the hwy then with AOD plus i run a 28inch tall tire.
my normal hwy speed is 110Kms or 60 65 mph with tack running at almost 3000RPM

03-12-2005, 05:32 AM
Hey Chirp 3.73s even 4.10s ain't nuthing with overdrive... I run a short 24.5"(225/50/16) tire on my Bird because I only have 3.73s...

You guys outta try runnin 4.11-4.56s without O/D like we did in the old days.. Hell the '69-'71 428/429 Super Cobra Jets got 3.91 or 4.30s from the factory and with a 50K mi warrenty to boot.

Consider this, the 5 speed TCs only have a 20% (.8) 5 th gear, so 3.55s wind up being a 2.84 final ratio. The 3.73s would = 2.98(not sure of the O/D ratio of the TC A4LD automatic). With the 30- 33%(.63-.67) OD of a AOD or V8 T5, final ratios would be 2.37(3.55) or 2.49 for 3.73s and even 4.10s is only a 2.75. Thats still less than the 3.00 ratio that was in the average 351 family sedan 30 years ago. Plus they didn't have lockup converters so actual ratio was more like 3.25....

True with a T5, 3.73-4.10s are a little steep in 1st gear due to the 3.35 ratio(the Ford Racing T5 with 2.95 is better), but us automatic guys(2.40 1st) need all the help we can get... One of my freinds runs 4.30s in a Bird with a AOD and 4000 stall and drives it on the street and to the track...

So my answer to 4.10s in a 3.8 AOD automatic... GO for it.... BUT 3.73s with a 2400 stall converter would be a better choice.

03-13-2005, 09:27 PM
i'm thinking about getting 4.10s myself. no overdrive. at least until my power level goes way up. like... unstreetable up. a buddy of mine bought a rear end that had 3.73s. that thing ripped. turns out it has 4.10s. i hooked.