I have a 5-speed manual V6 and want to change the gears and was wondering which of these two are a better. 3.73 or 4.10? Also, should I install a spedo adapter to compensate for the changes in gears? Will I need to reflash? Thanks!
Good question, depends on what you want to do with your car. 4.10s will lower the top end speed while increasing RPM, so if you commute long distance on freeway probably not a good move--3.53 probably better bet for commuter. If you get programmer that allows you to change speedo ratio, at least you'll be able to tell how fast you're going (this may take some tire conversion creativity).
Now, if you put on CAI, plenum, high flow cleaner, under pulleys, SCT it(http://www.mustangtuning.com/sctxc9.html), low profile wide tires, shocks, rear sway, lowering kit and 4.10s...you'll have a blast buzzing the streets and rallys when playing with those rice burners...
Have fun!
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(Still have) 69 Grabber Green Mach 1 Fastback
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Vintange 45 wheels with Nittos
3.73's? or 4.10's for the v6 5spd? Think no further.....
The Myth: I just put in 4.10's in my 2002 v6 5spd, and its well worth it. Everyone says you will have really high rpms, terrible gas milleage ladeda..... only somewhat true. Jumping from the 3.23's that come in this car to the 4.10's big difference in a good way. Way more pull from 3rd and fourth gear, huge difference in first gear, you wont make it through an intersection without going higher than 3,000rms so shift into second, unless your punchin it.... but rpms are 500 higher than with the 3.23's. so if you are going from stock dont worry.
3.73 vs 4.10:The 3.73 will be less acceleration lower rpms and i found they are only better if you do lots of casual highway driving and even then only for fuel economy by keeping your rpm's down. Your quater mile time with the 4.10's is better when you have a stock v6 than it will be with the 3.73's. Your car doesnt have the power yet to bring you to speeds where gear recession will be an issue so 4.10's well actually improve your top end as well.Until you get ALOT of hp dont worry about the 4.10's being too much even with a 5 spd. Even with forced induction systems they work just fine.
Cost:But keep in mind this is not a cheap converstion or simple bolt on. My shop costs for this conversion were about $1,000.00 reason being, you pay $175 for the gears $400 for install plus you have to get a tuner or chip so you car will not think it is going 160 when you are actually going 120 and it will shut off if you try to pass someone on the highway. Also you can get it tuned for 91/93 octane and program your chip with dyno settings all for the same cost.So changing your gear to the 3.73 or the 4.10 will get you another 14hp right there. The tuner is $400 or $300 if you just get this chip and no tuner, but then you cant change your settings ie tire size octane, gears ect without pulling the chip out of your dash. So i would recomend paying the extra 100.
Install: a couple suprises with this install, get a bearing kit which is $135 and replace all the bearings and pins cause some of thim will break when taking them out anyways. The pin that actually holds the gears down is an issue when you replace the gears you will notice the 4.10s are thicker ie taller, so they cover the entrance whole into the diff, you will other have to buy a already machined one with a grove to fit over your gears or you will have to get your stock one machined, it WILL NOT fit with out it. And keep in mind anytime you put new gears in your car you NEED to break them in take it easy and work both the resessive side and power side of your gear by raising your rpms and letting them resede back down. Dont push your car for the first 1000km and after 2500km change your oil cause all the filings from the new gears will be in your oil.
So for all the time, labour and money that you have to put into getting new gears for a street car, 4.10's are a solid bet, cause you get your money's worth. When you stick your foot into the car it hops of the line. My little v6 SMOKES the stock 4.6's big part of that is the 4.10 gears. 3.73 gears if you want a little less pull because you need more highway driving. If you go long distances get ready to pay lots for gas with the 4.10's but in the city it wont effect your gas millage, as long as you keep your rpms down by shifting on time. You will just be in a higher gear than someone with the 3.23's or even the 3.73's. Regardless of rumours that is the truth, i know, i have the v6 5spd with 4.10 gears and have driven it all over. 4.10's ALL THE WAY
ok. since we are talking about gears if I used the 3.73 (GT & auto) what would be my top speed? currently I can do 145+. and since I travel alot between cites in the wide open desert. top speed is kind of important to me
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2007 GT Alloy Metal with Auto transmission.
JLT II CAI, Steeda UDPs , Steeda CMDP, Borla full exhaust (LT's + x-pipe + stingers) , Bamachips 95 octane Race/ Torque tune
CHE adj.panhard bar & brace, adj UCA, LCA and anti-squat brackets.
FRPP 4.10s
Don't think you could consider it a hijack anymore since the original thread was started 3 years ago (2005) but with 3:90's and an AUTO you should still be able to hit 145
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2006 GT black (AUTO)IUP Saleen supercharger:Saleen Super Shaker 3.2 pulley: GT500 fuel pump: Roush tensioner:XCAL2 :JBA Long tube headers:JBA O/R H-pipe:JBA axle back exhaust:YNOMAX Resonaters:Strange3:90 gears:TCI 3000:BMR upper and lower control arms with relocation brackets:Power house drive shaft:cervini ducktail wing: cervini side scoops
Don't think you could consider it a hijack anymore since the original thread was started 3 years ago (2005) but with 3:90's and an AUTO you should still be able to hit 145
I should have looked at the date. 3.90 sounds too much to me plus they are hard to find. I'm actually thinking of going more than 145MPH. just wanna see if someone had 3.73s and how fast can they go
thanks for the input
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2007 GT Alloy Metal with Auto transmission.
JLT II CAI, Steeda UDPs , Steeda CMDP, Borla full exhaust (LT's + x-pipe + stingers) , Bamachips 95 octane Race/ Torque tune
CHE adj.panhard bar & brace, adj UCA, LCA and anti-squat brackets.
FRPP 4.10s
3.73 gears vs. 4.10 
3.73's? or 4.10's for the v6 5spd? Think no further..... 
YNOMAX Resonaters:Strange3:90 gears:TCI 3000:BMR upper and lower control arms with relocation brackets:Power house drive shaft:cervini ducktail wing: cervini side scoops
