gear confusion
 

Hi there,

I posted yesterday and asked if I should go 3.55's or 3.73's on a 93 GT. 2 people answerd I should go w/the 3.73's. So I was going to do that. Then 3 locals told me no, go w/the 3.55's. All the mustang books say go w/the 3.55's. I'm not second guessing any one and I am leaning toward the 3.73's, I just dont want her reving at 3 G's at 75 MPH. I've heard that 3.73's work best in an auto (mine's a stick).Can any one with 3.73's let me know what they think? I've heard rumors of speedometer troubles too. Gotta buy the gears Tuesday night to get'm here 4 the weekend. Any more input would be welcome.


Jayson

Most people say 3.55's are the best overall gear to get. I had 3.73's for a year and never liked them. I'm running regular radial tires so taking off hard off the line isn't real easy without spinning. Third gear with the 3.73's didn't pull that hard, but on the freeway my rpm's weren't that high. Around 2600 at 70-75. If you drive mostly in the city then go with the 3.73's. If you drive on the freeway alot then go with the 3.55's.

A buddy of mine had the 3.73's in his '86 and he ended up putting
in the 3.55's in because of all the freeway driving he does. Plus he drives it on the freeway like a screamin' demon! It did tach out around 3k at 75mph too. Get the 3.55's if you get on the freeway frequently and go well over the limit.

You will get a few different opinions on this one as this topic has been debated for years and years to come....here's my thoughts :)

I have had both the 3.55's and 3.73's in my 87 GT with a T-5 and a Tremec 5 speed.

I myself prefer the 3.73's with my set up, the car likes to run at a little higher RPM and the 3.73's are just right. Now my car is a fair weather car and just a toy, so gas mileage and highway RPM is not a concern to me.

For a naturally aspirated car I like the 3.73's, on a supercharged car I like the 3.55's. An AOD I like the 4.10's....

Sounds like 3.55's are my best bet. I'm an Army officer and I have a funny feeling uncle sam will send me to Germany next year. No speed limit on the Autobahn and I'm allowed to take one car. Even if I don't go to Germany I would like the option of driving it on the freeway without reving the crap out of it.

Jayson

I drive the higway everyday 80mi round trip's, i like to cook along about 75-80 mph, my car with a t-5 turns under 2500 at 80 mph, when i get another car to drive, 3.73s and maybe a blower are going on, i'll tell ya, these 3.27's arent easy to launch sticky tires on, at the track.

i have a 91 GT and i put 3.55's in it a few years back and i think it is the perfect gear for me. i do about 50/50 highway driving and go to the track occasionaly. I also went from and aod to t5 and with both transmissions they did good. When i went to a t5 i went with the svo heavy duty t5 which has a .63 overdrive instead of the .68 and this dropped the rpm even further its like taking off with 3.55's and having 3.27's with overdrive. I think chevrolet hit it on the head when the put in a 6 speed, there overdrive is .50. My dad has a z28 and when he is in 6th gear (he has 3.42's) his car did the same rpm when i had my 2.73's. so its kinda like you get the best of both worlds. I would like to in the future to somehow be able to install the chevrolet 6 speed in my car or just get the gearset to put in the ford 6 speed. Then i would be able to put 4.10 or 4.56's and for the freeway it would be like cruising with the 3.27's or 3.55's

I just bought me gears about a month ago and I, like you, had some concern about the 3.73's reving too high.

I went with the 3.73's and all I can say is that I love them. They are perfect, even for my car with the stock heads and intake (which restricts me from pushing much past 5,000 RPM).

In the city they are great, I even noticed and INCREASE in gas milage over my stock 2.73's! On the highway they are fine, I don't do alot of driving over say 65 mph, but I do go 60mph a fair bit and I have no complaints.

There is not going to be a big difference in RPM from 3.55's to 3.73's at highway speed, I bet only a couple hundred RPM.

Even with the 3.73's I can see why people install 4.10's.

Just my take on it.

I have the 3.73 and although i don't drive much on highway the time i do my rpm's are no more than 2500 at 75 mph and my gas mileage was 25 when i kept it around 70. one time with my friedns we was crusing at 80-85 and rpm's then was under 3000.

How about for an Automatic car, looking to eventually push 450 horsepower? 3.55's?

I've got 3.73's and I travel from CA to AZ all the time with no problems. I'd never go up to 3.55's.
Dave