Posts: 1655
Joined: 6/14/2003 From: Poplar Grove, KY Status: offline
<P>From the factory mustangs usually come with a 2.73 gear ratio unless you have an svo which in '84 they come out with 3.45 and in '85 and '86 3.73 was standard. Yoe had 2 options for different gearing in mustangs: 3.08 for 5-spd cars and 3.27 for autos. Changing the gears is one of the first things that i would do to a stang. Then we get into choices of different ratios. so here is my opinion on this subject. First you have to decide what you want to do with your mustang. Is it going to be a daily highway driver? A Sunday Driver? Will you be stuck in the city(stop and go traffic)? or just a weekend dragracer? You basically have 6 choices for gears: 2.73, 3.08, 3.27, 3.55, 3.73, and 4.10. the first 3 gear ratios are better for top-end, high speed performance, and the all important fuel economy to the highway commuters. 3.73 and 4.10 are better for acceleration and low end responsiveness. the gear ratio that i have left out was 3.55. it is kind of an all around gear you get fuel economy and still have the power to pass cars at will on the free way.</P>
Posts: 1655
Joined: 6/14/2003 From: Poplar Grove, KY Status: offline
MORE THAN LIKELY YOU HAVE A 7.5 REAR END AND I WOULD RECOMEND THAT YOU CHANGE IT OUT FOR AN 8.8 REAR. THE GEARS ARE PROUBALLY 2.73. I WOULD GO BACK WITH SOME 3.55 BECAUSE YOU WULL NOT HAVE ANY OVERDRIVE UNLESS THIS IS JUST GOING TO BE A RACE CAR.
Theres nothing wrong with that 7.5 rearend as long as you dont go running slicks on it!And being that it was a 2.3 and a 5 speed it most likely has anywhere from 3.08's to 3.55's.My 1989 2.3 with an A4LD had 3.73's from the factory.And i am still currently running the 7.5 and have been for 3 years now behind a 331 with no problems at all.
Now thats not to say everyones is that good.If you can or you happen to run across an 8.8 for cheap i would get it for sure and atleast keep it until the 7.5 gave out.But running around on the street on regular radials you shouldnt have a problem.
To tell whats in your rear look at the rear axle tag or lift the car and count how many times the drive shaft turns in comparison to the rear wheels.
Posts: 2045
Joined: 12/18/2003 From: United States Status: offline
hey buzz stang having a good day???i tryed every gear possible,,so i know first hand,,so call me ...i had ,,3.27,,3.73,,4.10,,4.30..i swap back and forth so much am going crazy
Posts: 490
Joined: 6/25/2003 From: United States Status: offline
Yeah, I'd like to know too, some of you say you've switched a few times, but the local shop said they wanted $600 for parts and labor, so I know you arent paying that much.
Posts: 270
Joined: 4/26/2003 From: United States Status: offline
Most of the mustang folks recommend no higher than 3.73 for 5 speed and 4.10 for aod street cars.
If it is modified for street/strip, you can go as high as 4.10/4.30 so trap rpm's will be in the 6000rpm range depending on tire diameter, etc.
It is also recommended that if it is turbo or s/c, no gear higher than 3.73, as you're going to be romping and stomping at the 1/4 mile mark.
3.55's will disappoint you if you even take a ride in a car with 3.73's. You will really get your jolly's if you run 4.10's, but don't get p.o.'d by the mileage, cause it will go away pretty quick. Just depends on what you want the car to do. I hate hearing people say they're worried that they're mileage will go south. If that's a problem, keep the stock gears and run consistant low 15's.
Posts: 490
Joined: 6/25/2003 From: United States Status: offline
Well, any one driving a V8 Mustang shouldn't care about milage in the first place, right? So anyways, what have you paid for ring/pinion installations?
Posts: 14
Joined: 2/6/2004 From: United States Status: offline
Low fuel mileage is well worth the fun and excitement you get out of these cars. Can anyone that had their gears done give me a rough idea of what it should cost me to replace mine?
Posts: 270
Joined: 4/26/2003 From: United States Status: offline
You're going to pay close to or right at $200 for the gears, whether they be frpp or richmond. Some sell cheaper, but you get what you pay for. Mine were frpp and came with all holes chamfered and gears deburred.
I believe I paid $175-$200 for the install thru a local speed shop. I don't trust pep girls or one of those outfits.
Posts: 39
Joined: 4/27/2003 From: United States Status: offline
Since we're talking gears. What is the ratio for the '84 GT. I counted and got 3.00, but I cannot find any info that states that that was ever available.
A friend runs the parts department in the local ford dealership and introduced me to a tech in the back who said 150 to install them as long as i bought the gears from ford.
I think someone is raping you guys royally hell for the amount you guys are spending you could almost get new heads.
And according to a ford tech book they have up there the 2.3's were geared at any where from 3.08's to 3.55's in the manuals and almost always 3.73's in the A4LD autos.
The 5.0's were 2.73's-3.55's in the manual and auto.
I looked my 7.5's up and factory it has a 3.73 with traction lock.
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