My dad has a 86 Mustang LX with the fuel injected 5.0HO moter and 5-speed in it, and where thinking of putting a lower rear end in it to give it some more balls without breaking the bank. I was wondering if anyone had done anything like this and what size gear we should use, he really doesnt want to give up too much top end speed. 4th gear has a long way to go before wind resistance overpowers the car (@ almost 150MPH) let alone 5th, so I'm guessing we have some room to play with. The only downside of doing this for me is that it will mean it will make his car take off faster than mine, and I'll loose my bragging rights, but what ya gunna do.
I put 3:73's in my 83 Mustang and I love them. Hard launches and still plenty of top end.
1983 was a Fox body too right? I cant ever remember the model years for Mustangs, although I should considering all the Mustang books my dad has.
My friend has 3.73s in his and he swears by them.
05 M6 YJ GTO 1 of 447 12.767@109.93
4.10 = what I've got. Depends on your tire size some IMO, but 3.73 or 4.10 is pretty much the standard for a N/A 5.0
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my buddy had an explorer rear end in his. think it was a 3:55 ?? hes planning on going to either 3:77 or 4:10s next.
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12.5@116 2.0 60ft 19psi
Too bad I don't know what the stock rear end is for reference, but I do know the thing will almost burry it's 85mph speedo in 2nd gear.
4.10's FTW. If he wants to go in the middle of 3.73's and 4.10 they do make a 3.90 gear....but I'd just go with 4.10's.
My cars gets around 17-18 mpg in the city and around 20 mpg on the highway with the 4.10's on a 144k miled motor. 4.10's are not bad at all on the highway either. Don't listen to what people will tell you about 4.10's on the highway. As long as you don't plan on doing 80mph+ all the time it will be fine.
'02 S-10 ZR-2 & '89 Mustang LX Hatch
My car:
http://videos.streetfire.net/video/4478be41-8f79-402a-85f1-98f3013c716f.htm
3:55 or 3:73 would be the best to go with a street car 5.0
with a more stock motor id go with the 3:55's , with some good mods id go with the 3:73's
Stock is either 2:73 or 3:08.
If you drive the car alot, like maybe as a daily, I would go with a 3.73 or 3.90. A 4.10 is a bit much for a well driven car sometimes. I've personally drove 5.0 fox bodies with both those gears in them and you won't be disappointed with either. It'll probably throw your speedo off a little bit no matter which you go with though, but it shouldn't be by too much. I picked up a 3.73 for my 4.6 car.
Still not lowered...
His car has a CAI, and dual glass packs with stock headders, otherwise, it's completely stock, the speedo doesn't work that well anyway. He basically want's the car to pin him to the seat and take off hard, but still be able to do 140+ mph on the rare occasion. From what I'm gathering (and knowing him pretty well) it sounds like 3:90 would probably be what he'd be the most happy with. If the car does around 77 to 84 in second now, then with a 3:90 rear end, it would probably do about 60 before you had to shift into 3rd right? thats kinda the ballpark I'm aiming for.
3:55 or 3:73 would be the best to go with a street car 5.0
with a more stock motor id go with the 3:55's , with some good mods id go with the 3:73's
Quote:
Not really. I would say 4.10's for mild mods...and step down to 3.73's when you start to get some more serious mods (besides bolt on's) like forced induction.
it would probably do about 60 before you had to shift into 3rd right
Quote:
Probably around 55 or so. Tell him to go with the 3.90 or 4.10. Trust me. It makes a HUGE difference!
'02 S-10 ZR-2 & '89 Mustang LX Hatch
My car:
http://videos.streetfire.net/video/4478be41-8f79-402a-85f1-98f3013c716f.htm
Lash wrote:
3:55 or 3:73 would be the best to go with a street car 5.0
with a more stock motor id go with the 3:55's , with some good mods id go with the 3:73's
Quote:
Not really. I would say 4.10's for mild mods...and step down to 3.73's when you start to get some more serious mods (besides bolt on's) like forced induction.
it would probably do about 60 before you had to shift into 3rd right
Quote:
Probably around 55 or so. Tell him to go with the 3.90 or 4.10. Trust me. It makes a HUGE difference!
Some stangs have 3.27 gear stock so a 3.55 will barely be a upgrade at all if that is the case. 3.73 or 4.10 is pretty much the standard for a N/A 5.0 if you have a power adder things like tire diameter and 1/8th or 1/4 mile racing starts to be important to consider. My car has 4.10's and I drive it on the highway all the time.
If you wish to know exactly how much RPM a car will pull in a certain gear just use these pages below and your head.
http://www.angelfire.com/fl/procrastination/rear.html
http://www.1010tires.com/TireSizeCalculator.asp
http://www.angelfire.com/fl/procrastination/rear.html
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