Finally got the gears broken in enough to actually start driving her hard again, and I know there's a million threads that are "What gear should I choose", so I'll post up my thoughts and reviews of running a 4.10 gear in a 5 speed, 2V car.
The good:
Feels like a totally different vehicle. Really added to the attitude of the car, and makes it really fun to drive over the stock 3.27's.
5th gear is actually useable below 60mph. My 3.27's were always ticking me off when I had to slow down to 50mph, and then try to accelerate back up to 60-65mph, and there was nothing there. Now 5th gear is reponsive from 45mph and up.
My fuel mileage in town during the break in period, went up 4mpg. Attribute part of that to the reduced throttle input needed to get up to speed, and the other part to me driving like an old man.
The bad:
60mph is now 2200ish rpms. If you do a lot of highway driving above 70mph, this may not be the gear for you. However, short jaunts on the highway are not bad. I would drive to Myrtle Beach with these on my car, which is about 2 hours away. Probably wouldn't drive across the country though. Part of this is because at those rpms, my exhaust is pretty darn loud, and would drive me crazy.
So my final recommendation for gears:
If 75% or more of your driving is in town, or on back country roads, or secondary highways (55mph), then 4.10's are the perfect choice for a naturally aspirated car. If 75% or more of your driving is highway driving, then 3.73's may be better for you, if you have a loud exhaust and would like to stay sane.
Those were the gears I was planning on getting for mine, thanks for the review. You said you finally broke them in, are you supposed to ride easy for a while after installing them?
When they put my 4.10s on they said go easy on them for a week, then come back to get the oil changed on the gears because it would have a bunch of metal shavings in it that needed cleaned out.
I assume that's why you go easy on it.
And I feel the same way about these gears, great with minimal highway driving!
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40th Anniv. Black GT
K&N CAI, Stage 2 Clutch, 4.10s, Hypertech Tuner
That's all I've figured out how to do so far!
Yea I just got my tranny replaced and I got 4.10 I went easy on it for a day or two the guy said just drive it normal so. I haven't layed it down but I have been throtling it.
4.10's are ok 0-60 is insane fast but after that I hate 4th in it.
Do the Bullitts have the Tremec 3650 or the T-45?
The overdrive gear ratios are different with the 3650 being more highway friendly. If I had pre 2001 GT I'd go with 3.73's. 2001+
4.10's!
I've had 4.10's in my 95GT and drove from East TN down to Biloxi MS,then from Biloxi to wichita falls TX, then from wichita falls to Sumter SC. I don't mind the rpms at all and they are a great gear to have. Heck my 05GT had 4.30's and I drove to my parents house in TN, 5 hrs away, and they were fine. Almost 3K cruising but didn't bother me.
Some say to break them in and others say there is no need to. I would definitley break them in though, about 500 miles on being easy.
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1995 Mustang GT-Heavily Modded-Sold 2003 Ford Lightning-Sold 1997 Saleen-5.4 conversion-Sold 2005 Mustang GT-Torch Red-Sold 2003 Mustang Cobra-Oxford White 2003 4Runner V8 Sport Edition 4X4
I have a '99 GT, manual tranny, supercharged, and I friggin love my 4.10s. I can literally destroy tires on command. I don't go around doing burnouts for no reason, but opening up the throttle and pitching the rear end out sideways around a corner is the cats ass. Who wouldn't want to do that?
My car is loud too. I just ordered some JBA headers. I'm doubting those will quiet it down a whole lot.
I agree with not wanting to drive the car cross-country. You'd need earplugs. I was getting 70 mph at about 2500 rpms. I actually haven't driven the car enough to pay attention to the rpms at certain speeds with the SC though.
Cruising around in town with 4.10s is pretty great, and yeah, you can actually accelerate in 5th.
I've heard that the gears should be heated, allowed to cool down for a few cycles to temper them and the bearings during the break in period so they'll last longer.
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'99 GT - My increasingly expensive DIY project car... Vortech V1, Moser 31-spline axles, FRPP diff. w/ 4.10 gears, Steeda Tri-Ax Shifter, Shany Custom pipes, JBA shorty headers, Powerslot rotors, Tokico D-specs, H&R Sport Springs, Steeda Strut Brace, MM X-duty Lower Control Arms, Autometer Phantom Boost and Wideband AFR guage, Custom Rear seat delete, Royal Purple, NGK, BFG
Holy sh*t dude...You hit 13.34 @ 102 with stock gears???? What mods did you have and how much rwhp?? Thats impressive.
Glad you like them. I love mine, I do like 80mph on the highway and its below 3000rpm. At 90mph its at 3k rpm. Doesnt bother me too much, and Im running SLP LM1 with o/r Prochamber.
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2003 Mustang GT Redfire 1/4 Mile - 13.408 @ 103.10mph | 60 Foot - 1.934 261rwhp & 284rwtq Tuned by Mike Dez @ Dez Racing
4.10's, SLP LM 1 Catback, Mac o/r Prochamber, K&N FIPK II CAI(painted red), MAC 70mm TB, C&L Plenum, Diablo Predator Tune, B&M Short Throw Shifter, Mach 1 Chin Spoiler, Mach 1 Grill Delete Next Mods - Saving for a Procharger :)
Holy sh*t dude...You hit 13.34 @ 102 with stock gears???? What mods did you have and how much rwhp?? Thats impressive.
Glad you like them. I love mine, I do like 80mph on the highway and its below 3000rpm. At 90mph its at 3k rpm. Doesnt bother me too much, and Im running SLP LM1 with o/r Prochamber.
Mods when I hit the 13.34@104 weren't much, just did the right stuff to drop my times, and driving the crap out of it.
Tunable Induction CAI
UPR Off-Road X Pipe
weld in flowmasters
HPM Megabite SRs set to the 135% setting, and pinion angle set at -2 degrees
BFG Drag Radials (the old good ones) set at 18psi
Tuned by Pro-Dyno
passenger's and rear seats removed, along with everything in the trunk.
Launching at 4500rpms, slipping the crap out of the clutch, and power shifting at 5700rpms gave me my best times.
To be honest with you, on my mail order tune, without the drag radials, I ran a 13.8@101. Just adding the drag radials, I dropped to a 13.5, and then the new tune combined with cooler weather netted me a 13.34. Now, with the 4.10's, I'm going to step up to M/T drag radials, and shoot for a 12 second timeslip in the cool November air.
Wow man that is very impressive man. I was trying to hit 12's without cracking the motor or putting Longtubes on. But up here, the track is closed til April
I was full race weight with no suspension mods. I hit a 13.408. But you know, I dont think my tune is giving me enough fuel. Its not fattening up til about 4,500rpm. My tuner (Mike Dez) said he kept trying to dump more fuel in it, but it wouldn't fatten up.
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2003 Mustang GT Redfire 1/4 Mile - 13.408 @ 103.10mph | 60 Foot - 1.934 261rwhp & 284rwtq Tuned by Mike Dez @ Dez Racing
4.10's, SLP LM 1 Catback, Mac o/r Prochamber, K&N FIPK II CAI(painted red), MAC 70mm TB, C&L Plenum, Diablo Predator Tune, B&M Short Throw Shifter, Mach 1 Chin Spoiler, Mach 1 Grill Delete Next Mods - Saving for a Procharger :)
You guys are getting some damn good times from mildly modded 2 valves or maybe the guys with them around here just suck cause I hardly ever see one break 100 mph in the quarter with similar mods. Makes me respect them more!
Thanks bro. Yea if I had just control Arms I could have done better. 2nd gear was alittle squealy for me everyime. And launching, I still needed to feather the clutch. I probally would have turned that 13.408 to a very low 13.3 or 13.2. And ran consistent 13.3-4's.
But Bullitt5339 can drive the hell out of his car. 13.34 @ 102 with not much at all is very very impressive
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2003 Mustang GT Redfire 1/4 Mile - 13.408 @ 103.10mph | 60 Foot - 1.934 261rwhp & 284rwtq Tuned by Mike Dez @ Dez Racing
4.10's, SLP LM 1 Catback, Mac o/r Prochamber, K&N FIPK II CAI(painted red), MAC 70mm TB, C&L Plenum, Diablo Predator Tune, B&M Short Throw Shifter, Mach 1 Chin Spoiler, Mach 1 Grill Delete Next Mods - Saving for a Procharger :)
Nice dude that thing is bad. Alittle hard to see the speedo, but I know where the shift points are on a 2V lol. Except 1st gear, 1st wraps up so effing quick.
I have a Flip Video Camera, I can accually get it to stick in my steering wheel and hit the speedo good. Ill try to get a video and post mine tonight....tonights a good night to open her up, cool air no work tomorrow..lol.
When you going to get to the track? Im very very interested to see what you can run.
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2003 Mustang GT Redfire 1/4 Mile - 13.408 @ 103.10mph | 60 Foot - 1.934 261rwhp & 284rwtq Tuned by Mike Dez @ Dez Racing
4.10's, SLP LM 1 Catback, Mac o/r Prochamber, K&N FIPK II CAI(painted red), MAC 70mm TB, C&L Plenum, Diablo Predator Tune, B&M Short Throw Shifter, Mach 1 Chin Spoiler, Mach 1 Grill Delete Next Mods - Saving for a Procharger :)
4.10 gears in a 5 speed review 
