Ok so here is my situation. My car is my daily driver right now. I'm trying to decide between 3.55's, 3.73's, (POSSIBLY 4.10's, some say "don't fear the gear"). Anyway, my car has mild mods as u can see from my sig and my next mod will be gears, my friends IROC-Z28 w/ a 305CI engine says he "doesnt drive" in the rain (cause he cant w/ 3.73 gears), and being that i live in seattle...well you get the idea. I am going to drop a 347 stroker w/ AFR 185 HEADS in eventually. BUT i dont plan on this being my daily driver, i'm hoping to have a honda civic or something as a daily driver by winter but it may not happen, my question is, should i get 3.55's or 3.73's, my mechanic says 3.55's, but i wanted to know how much difference 3.73's COMPARED would REALLY make. because i dont know how long it would take me to get the new FWD car that i want as a daily driver. and the 347 wont go in till winter also anyway...THANKS FOR YOUR TIME. ALL OPINIONS AND EXPERIENCES WELCOME!
Gears?!?
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Please never say that again (I happen to hate that phrase!).custom89stang said:
What do you have tire/adhesion-wise? That makes a huge difference.
With mods planned and that the car might not be a DD forever, I would go with 3.55's. But MOST everyone else will say 3.73's (I just like lower numerical gearing; I am in a huge minority). If you have to jump on the highway much, I am not sure that 4.10's would be great. You should be making decent power as it is.
Do you have any buds who have gears in a stang - can you take a test drive?
I know I did not help, but tire info and the type of driving you do would help people to give advice, IMHO.
Good luck.
Dbeck002
New Member
when a car starts making a lot of power you usually want a softer gear like 3.55s... because you want to actually use the torque of the engine and not waste it by needing to rev high.. V8s use torque as their magic.
Personally i went with 3.73s because my car has mild mods and i need steeper gears.. with a 347 and AFRs the 3.73s are not needed, 3.55s is ample gear and your friend is right; i never drive my car in the rain either because its very tricky and dangerous with steep gears.
I would get 3.73s or 4.10s only if it was a track only car and had slicks to handle the 347s torque.
Personally i went with 3.73s because my car has mild mods and i need steeper gears.. with a 347 and AFRs the 3.73s are not needed, 3.55s is ample gear and your friend is right; i never drive my car in the rain either because its very tricky and dangerous with steep gears.
I would get 3.73s or 4.10s only if it was a track only car and had slicks to handle the 347s torque.
Michael Yount
Mustang Master
As a practical matter, there is so little difference (less than 7%) between 3.55's and 3.73's that you wouldn't be able to tell the difference if you simply rode in similar cars with both gears. Toss a coin -- get the ratio you can get the best deal on. Don't forget to adjust for the speedometer error. I doubt you want 4.10's unless you're strictly racing the car - even then you make final adjustments with rear tire diameter.
Aliate X
Member
I have 4.10s, would never put anything else in a N/A car. You have to remember, when you make more power, 4.10s will be less intense because with horsepower comes more top speed.
If you have a good set of tires (275 nittos), 4.10s is the way to go. Nittos are good in the rain as well as a good street drag radial that has good tread life.
If you have a good set of tires (275 nittos), 4.10s is the way to go. Nittos are good in the rain as well as a good street drag radial that has good tread life.
maverick0716
Founding Member
I have 3.73's and it's just fine in the rain....hell I even drive it in the snow. That's with the 3.35 first gear too, which is gone in a flash.
PhLoBuS
New Member
Decide on your combo before you pick a gear. 3.73 minimum. I'll be doing MUCH needed 4.10's in my new 347 eventually. Gotta recover from my spendings first. As someone with a 3.73 geared 347, I kinda know what i'm talking about
I daily drove my car with h/i/c, 3.73's and drag radials. It was fine, just gotta be careful. I remember being on the highway at 65 in the rain, zero issues.
I daily drove my car with h/i/c, 3.73's and drag radials. It was fine, just gotta be careful. I remember being on the highway at 65 in the rain, zero issues.
89CopCoupe
Banned
My street 331 notch has 3.55's and a T5Z
My stockish 302 notch has 3.73's w/ an AOD.
The 3.55's are perfect for me for all around use ... half my desired driving is on the highway and it's fun sometimes to go for long cruises.
The 3.73's are a little too low geared for my tastes, although it isn't horrible ... the car always feels between gears though.
Example: My stockish engine's cruise-spot is about 1700-1800 rpms ... at 42mph I'm at 2100 in D and 1300ish in OD
At 65-70mph on the freeway I'm at 2200-2400rpms ... as you can see this is always outta the cruise spot for me when I drive this car
I'm actually seriously considering swapping in 3.55's to this car also, as it will be closer to just right, for me personally.
Again though the 3.73's aren't horrible, they just always feel a tad too low for casual use.
Just my 2 cents from a fellow Puget Sounder
My stockish 302 notch has 3.73's w/ an AOD.
The 3.55's are perfect for me for all around use ... half my desired driving is on the highway and it's fun sometimes to go for long cruises.
The 3.73's are a little too low geared for my tastes, although it isn't horrible ... the car always feels between gears though.
Example: My stockish engine's cruise-spot is about 1700-1800 rpms ... at 42mph I'm at 2100 in D and 1300ish in OD
At 65-70mph on the freeway I'm at 2200-2400rpms ... as you can see this is always outta the cruise spot for me when I drive this car
I'm actually seriously considering swapping in 3.55's to this car also, as it will be closer to just right, for me personally.
Again though the 3.73's aren't horrible, they just always feel a tad too low for casual use.
Just my 2 cents from a fellow Puget Sounder
Michael Yount
Mustang Master
copcoupe - do the math before you swap the 3.73's for 3.55's -- they'll only drop your cruise rpm (65 mph) by about 130 rpm; no where near the sweet spot of 1600-1700 rpm.
amplifier28
Member
- Apr 16, 2005
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_jb_
New Member
I got 3.55s in my car. It's a DD in the summer, with a 347 coming. I will keep the 3.55s in for a while, after my engine is built and running. then it will be the time for a new tranny, which I'll probably get a Viper T56, since I do a LOT of highway driving.
My other tranny option is keep the 3.55s, and get a TKO500. 5th gear is .63, which is almost like the Viper T56, .5. Both trannies can take the power, but it's on you want you want. The T56 is about $1k more than a TKO500...
My other tranny option is keep the 3.55s, and get a TKO500. 5th gear is .63, which is almost like the Viper T56, .5. Both trannies can take the power, but it's on you want you want. The T56 is about $1k more than a TKO500...
I created an Excel spreadsheet for doing this a while back, here's what I got for you. It won't help predict the seat of the pants feel, but it may give an indication of what kind of economy to expect. Also drive the car at each of the following rpms and see what it sounds like. If that rpm produces a loud resonance inside the passenger cabin you may want to rethink that rpm range.
Assumptions.
65mph
25.25" Tire Diameter
.68 fifth gear
Calculated.
Gear 3.55 3.73 3.90 4.10
RPM 2,087 2,193 2,293 2,411
If you measure your tires and let me know if your fifth gear is different I can run the numbers again. Is 65mph a typical cruise speed for you. Around here the speed limit is 60 to 70. I am usually in the 70-75 range myself.
Assumptions.
65mph
25.25" Tire Diameter
.68 fifth gear
Calculated.
Gear 3.55 3.73 3.90 4.10
RPM 2,087 2,193 2,293 2,411
If you measure your tires and let me know if your fifth gear is different I can run the numbers again. Is 65mph a typical cruise speed for you. Around here the speed limit is 60 to 70. I am usually in the 70-75 range myself.
89CopCoupe
Banned
Michael Yount said:
Yeah I hear ya ... that's why I said "closer to just right".
I've also considered maybe 3.27's, but I might miss the extra low end generated by the 73s or 55's too much with the taller geared AOD (comparatively) ... I spend about 75% of my time driving the car about 40-45mph so the 3.55's might be the perfect trade.
Although I still have my SSP that I'm completely satisfied with
