8.8 Gear Help Needed

[84StangSVT]

I opened the differential this evening and I need to know what I have. I'm assuming I currently have a 3.27 gear but I'm not for sure.

The numbers on the main gear are....
3 327 E6ZA AA 17 36 2A B

I have no idea what this rear came out of but I know it's not the factory rear. Any help is appreciated.

[83gt351w]

3.27 it is. Not THAT common, as most were 2.73 or 3.08.

[Jerry peachuer]

1986 gear (e6)

[83gtstang]

The 327 was for the automatic car I believe.

[cmgramza]

My 86 4cyl auto car came with a 3.27 gear...

[grabbergreen84]

Does it have Traction-Lock/posi?

[84StangSVT]

Does it have Traction-Lock/posi?

It does appear so

[Ethyl Cat]

Count the ring gear teeth, count the pinion teeth and divide the ring gear count by the pinion count.

[Travis T]

Same red goo that was on my "3.27" axle so it's been opened. Too bad you didn't find 3.73s like I did! Guy I bought it from sold it to me because it didn't have 3.73s in it! He should have marked it and counted revolutions like I did haha.

[84StangSVT]

Same red goo that was on my "3.27" axle so it's been opened. Too bad you didn't find 3.73s like I did! Guy I bought it from sold it to me because it didn't have 3.73s in it! He should have marked it and counted revolutions like I did haha.

Count the ring gear teeth, count the pinion teeth and divide the ring gear count by the pinion count.

I'm positive it is a 3.27 gear set since the 327 is stamped on the main gear. I can double check that tonight by counting the revolutions and even the teeth as you guys mention. I also assume that it is the Trac-Loc rear as when you rotate one axle, the other follows in the same rotation.

What would be the benefits and the downfalls of changing to a 3.73 gear as I have strongly contemplated that move. Being a basically stock 84 V-8, I'm assuming that the change in gears will help it accelerate quicker and have more "seat of the pants" power but will gas mileage suffer much and would the highway cruising RPM's be much higher?

[83gt351w]

If there was a "perfect" gear, the 373 would have that title, IMHO. When I switched from a 308 to a 373, the car was a different animal. The best bang for the buck, seat of the pants upgrade anyone can do. Mileage will drop a few mpg's, but it's a Mustang, not a Prius.

[84StangSVT]

If there was a "perfect" gear, the 373 would have that title, IMHO. When I switched from a 308 to a 373, the car was a different animal. The best bang for the buck, seat of the pants upgrade anyone can do. Mileage will drop a few mpg's, but it's a Mustang, not a Prius.

Good point LOL! Rear gears are something I have never fooled with or seen done, so I might have to find someone locally that is familiar with the 8.8 that can do the change for me if I decide to go that way. I would hate to get something out of whack there.

[Travis T]

You'll like the 3.27s in that car, that is actually what I wanted after swapping them in a different GT.

[ragtopjr]

If there was a "perfect" gear, the 373 would have that title, IMHO. When I switched from a 308 to a 373, the car was a different animal. The best bang for the buck, seat of the pants upgrade anyone can do. Mileage will drop a few mpg's, but it's a Mustang, not a Prius.

I agree, and what I found was that for my driving the 3:73 was actually better on fuel then any other ratio I had previously/since.... 2:73, 3:08, 3:55, , and 4:10....
I plan on sticking a 3:73 8.8 into my stock V8 Anny car next year....

[84StangSVT]

You'll like the 3.27s in that car, that is actually what I wanted after swapping them in a different GT.

As opposed to a 3.73? I guess everything is subjective to the person driving and I'm sure intended purposes for the car make a difference.

[83gtstang]

What transmission are you running? SROD, early T5, automatic, T5Z etc? I am happiest with my 3.73 and my 2.95 first gear T5Z. I remember with my old SROD and my 3.35 first gear T5, the car was very "jerky" and would spin crazy off the line, first was almost useless. Was fun though.

[84StangSVT]

What transmission are you running? SROD, early T5, automatic, T5Z etc? I am happiest with my 3.73 and my 2.95 first gear T5Z. I remember with my old SROD and my 3.35 first gear T5, the car was very "jerky" and would spin crazy off the line, first was almost useless. Was fun though.

This will be with the factory T-5, it's one thing that wasn't changed on this car. I'm not sure what gear ratios they are though, how would I find that out?

[Travis T]

The 84 I had it in was stock except for exhaust and the 3.27 fit it nicely. I haven't driven one with a 3.73 yet, but if yours is in good condition, I'd try it first and see how you like it before paying for a gear swap.

[83gtstang]

This will be with the factory T-5, it's one thing that wasn't changed on this car. I'm not sure what gear ratios they are though, how would I find that out?

I think you have the non world class T5 then. Should be a tag somewhere or run numbers on the cast somewhere. It's a 2.95 first gear I believe from reading, the world class was introduced in 85 and had a 3.35 first gear. My 83 came originally as a SROD four speed with a 3.07 first gear and was super with 3.73 gears.

http://chris66dad.tripod.com/id38.html

This link has a tag reader just type in the numbers

http://www.5speeds.com/t5/

[79347]

Read the tag on the rear

[steam_mill]

On my '85, I had 2.73 on the 7.5.

I upgraded to the 8.8 and it had 3.08. Gears made noise so I decided to have 3.55's in.

Better seat of your pants power.......at 70mph the drone was gone as the rev's are higher. Since this was my first experience with a gear swap, I was hesitant fearing too much gear.

Hindsight, I should have gone with 3.73. Seat of your pants is better.....but could have been better if I had gone with 3.73.

When I ordered my Jeep Wrangler last year....I ordered it with 3.73 instead of the stock 3.08. Heck I should have ordered the jeep with 4.10 but then I would have had to order a Rubicon and give up a posi rear end for lockers. I don't crawl and my jeep is my DD to get me to the hunt camp....Oops, this should have gone on the wrangler forum HEHEHE.

[embler]

Don't fear the gear

[JACook]

I'm one of the contrary ones that likes the 3.27s behind a manual better than I like 3.55s, let alone 3.73s.
Gear choice is not just about acceleration for me, I also care about how the car drives in stop-and-go, and
with 3.55s, 1st gear is all but useless in my '85 hatch. I end up doing about 90% of my acceleration in 2nd.

Maybe it's an age thing, but over the years, I came to the same conclusion with my 1st-gen Mustangs. My
'68 ended up with a toploader and 3.25s in the rear, and they're perfect for the way I drive. And that last
bit is the most important part. There are guys that put 4.10s in a 5-speed car and love them, so it really is
more of a personal choice, based on what's most important to you.

Automatics are a different story though, especially if it's an AOD. AOD cars can use just about all the gear
they can get.

[Jerry peachuer]

Ford used a 331 gear as well I have one its out of a 05 vert auto
Would make a perfect power adder gear ratio being between the two popular swaps

I had 327 355 373 and currently 410 and won't go back
430 is what I would go with if I had a aftermarket trans with the better overdrive

As far as 1st gear being useless I'm not sure what that means it's shifted in th middle of a intersection and your n second before you cross the intersection what else is first gear used for ??

Second gear off the clutch just over ideling is good for a very heavy traffic situation it will just do its thing no bucking or drive ability issues

As far as being a perfect mpg gear well no

I'm at 2800 rpm with 26.1 tall tire at about 65 (phone GPS mph) never switch speedo to accomodate gear swap

When I hear first gear is useless statement for a 410 should not consider no higher than 373 and if you want a 410 your not looking for the best mpg
Most cams and intake swaps Come alive in the 3200 rpm range

Try to get your power and there is easily done with gear swap

[Jerry peachuer]

Last sentence supposed to be To get in your power band range


If your curious how 3000 rpm is on the e way put it in a gear that will allow you to be a 3k around 70 prob 3rd gear or so

A 28 inch tall tire and a 410 is a option to lower cruising rpm s if a lot of e way driving is in your future

My car is not used daily and not much e way either