4.10 or ?

therzl

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I own a '96 Cobra with 110K miles. The engine is stock (and N/A). I've completed moderate suspension upgrades, MGW shifter...I'm considering swapping out the 3.27 gear with a 4.10 or 4.30. Any recommendations as to which ratio and why? Also, my stock clutch is going. I'm looking at the Exedy Mach 400 Stage 2 ($245 @ AM). It's a random consideration based on reviews I've read. Any suggestions regarding clutches, brands etc? Should I replace the clutch cable, and is a speedo gear a good choice for re-calibrating the speedometer? Lastly, if anyone happens to know, approximately where would the rpm be hovering at 65/70 mph if I installed a 4.30? Thank you for your time.
 

dkblue98gt

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I'm in the same position with my NA 97. I'm planning to replace the 3.27 with 4.10"s. Hopefully it will really wake the car up.

As far as the clutch, I was originally going to go with the Mach 400 then I decided to upgrade to the Exedy lightweight flywheel and go with the 11 inch Mach 500. You need new pressure plate bolts and and flywheel dowels. I"m very happy with the Mach 500, It has great manners on the street.

I would also suggest using a Motorcraft throwout bearing. Stock clutch cable should be fine but a new quadrant and firewall adjuster is nice. Speedo gears don't seem to work well on our cars. Most go with a Speedcal.
 

xblitzkriegx

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Stock tires and 4.10s = 2500rpm at 70mph. 4.30s will be 2700rpm at 70mph.

On a lightly modded car, you'll cross the line around 5500-5800rpm in 4th on 4.10s and around 5800-6100rpm with 4.30s.

1st gear mph differences between stock, 4.10, and 4.30 is 47, 37, and 35mph. Second gear differences are 79, 63, and 60mph.

Seat of the pants difference between stock and 4.10s is massive but 4.10 to 4.30 isn't as big a jump. 4.10s will make the car feel like it gained 50hp+.

Go with a speedcal. The gears get chewed up really easy as they don't last. The 23 tooth is used for the 4.10s but it barely lasts a year if you drive it a lot.
 

2000GTSTANG

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I had 4.30s in an 01 Cobra that was pretty much stock besides offroad midpipe and really enjoyed it. The car ripped through the gears and was really fun around town. I think you'd be fine with either choice and wouldn't dwell on it for too long.
 

therzl

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Thanks for your input. 4.10 should definitely jolt the car, but I've read 4.30s are perhaps preferable. With the 4.10 installed, if travelling 65/70 mph on stock 17" wheels (If I read correctly), the rpm should hover around 25/2,600, which isn't bad. I have concerns that a 4.30 will keep the revs rather high for excessive periods. True, the engine red-lines at 6800, and I love pushing the car, but...I'm hoping to hear from others with direct 4.30 experience. I'm curious, how did you come to initially choose the Mach 400, and why do you prefer the Ford throwout bearing?
 

dkblue98gt

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I saw the Mach 400 at Latemodel Restoration. Products they carry are usually pretty good in my experience.

When I got my car it had a small oil leak near the back of the oilpan. I thought the rear main seal was leaking...

Turned out to be the pan gasket. I like to replace the clutch on a new to me car anyway.

I saw Exedy also made a light weight flywheel and it would take an 11 inch clutch so I got the 500 instead of the 400.

Most Mustang guys will recommend the Motorcraft throw out bearing because most of the ones that come with clutch kits started making noise after a few thousand miles.

Sent from my Pixel 2 using Tapatalk
 

J.Rovirosa

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Have had 4.10's in mine for years and don't regret it a bit. Consensus has leaned toward 4.30's being the ideal gear especially if your car sees the strip and they'd probably be my choice with a T56. But with the T45, I feel 1st gear is still long enough to be usable on the street and prefer the slightly lower cruising rpm with the 4.10's. Should've been what these cars had from the factory, with 4.30's or 4.56's being what everyone swaps in for straight line duty.
 

therzl

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Thank you all for responding to my questions. I greatly appreciate your time, knowledge and insight. I've decided to go with the 4.10s and will likely replace the LSD discs with the FP carbon Traction-LOK re-build kit (and a 28 spline S-spring). Thanks again.
 

Tabres

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You won't be disappointed with the 4.10s. They really pump-up the fun factor driving these cars when naturally aspirated. A lot of people think I'm crazy when I say this, but the most enjoyable setup I ever had in my car was when it was a bolt-on, light suspension work car with 4.10 gears.

If you're looking for a speedcal to correct your speedometer after the gear swap, I have an extended range version I'll be removing from my car soon and will be selling for a reasonable price. Feel free to reach out if you're interested.
 

shurur

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Not sure speedcal is around anymore..better take the above offer from Tabres
 

therzl

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You won't be disappointed with the 4.10s. They really pump-up the fun factor driving these cars when naturally aspirated. A lot of people think I'm crazy when I say this, but the most enjoyable setup I ever had in my car was when it was a bolt-on, light suspension work car with 4.10 gears.

If you're looking for a speedcal to correct your speedometer after the gear swap, I have an extended range version I'll be removing from my car soon and will be selling for a reasonable price. Feel free to reach out if you're interested.
You won't be disappointed with the 4.10s. They really pump-up the fun factor driving these cars when naturally aspirated. A lot of people think I'm crazy when I say this, but the most enjoyable setup I ever had in my car was when it was a bolt-on, light suspension work car with 4.10 gears.

If you're looking for a speedcal to correct your speedometer after the gear swap, I have an extended range version I'll be removing from my car soon and will be selling for a reasonable price. Feel free to reach out if you're interested.
 

Tabres

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Yes, I'm possibly interested. Could you please tell me what this device is and how it functions? Also, how old is it?

Here is good product description of it. Essentially it is a electronic device that wires inline with your vehicle speed sensor and modifies the signal sent to the dash from the VSS to correct for rear-end gear changes, tire changes and transmission changes. It's only a few wire hook-up and setting a series of dip switches correctly for your setup. I've had it in my car for roughly 5 years. Works flawlessly, I wouldn't be removing it if I weren't switching to a Holley EFI setup.

Product description: Mustang Speed Calibrator (94-04 Manual & 94-98 Automatic)

Install instructions: Mustang Speed Calibrator Installation Guide | AmericanMuscle

Please feel free to personal message me if you're interested.
 

adammdennis11

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I own a '96 Cobra with 110K miles. The engine is stock (and N/A). I've completed moderate suspension upgrades, MGW shifter...I'm considering swapping out the 3.27 gear with a 4.10 or 4.30. Any recommendations as to which ratio and why? Also, my stock clutch is going. I'm looking at the Exedy Mach 400 Stage 2 ($245 @ AM). It's a random consideration based on reviews I've read. Any suggestions regarding clutches, brands etc? Should I replace the clutch cable, and is a speedo gear a good choice for re-calibrating the speedometer? Lastly, if anyone happens to know, approximately where would the rpm be hovering at 65/70 mph if I installed a 4.30? Thank you for your time.
you'll love the 4.10's
 

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