Right now I have 3.08s in my 86 mustang. The Motor is built pretty well and it's pretty fast. I'm Just wondering if I should swap out the stock gears for some 3.55s I have out of my f150. The gears are in good shape i just replaced them for 4.56s in my truck. Think I should just toss them in. I've installed gears before and I have a pro mechanic to help out if needed. Is it worth the switch for the amount of balls im gonna get vs. paying 100 bucks for an install kit?
3.08 Swap to 3.55?
- Thread starter mooktank
- Start date
TRWXXA
Member
If you have a 5-speed, the 3.55s will wake your 'Stang up pretty well. If it's an AOD, I recommend 3.73s. But if you already have the gears, it'd definately be worth putting them in.
Since the gears are used, I'd expect that the rear end will be a bit noisey unless you can get them to mesh exactly as they did in your F150.
Since the gears are used, I'd expect that the rear end will be a bit noisey unless you can get them to mesh exactly as they did in your F150.
408stroker5.0
The world would be a better place if all males jus
I'd try and sell the 3:55's and go with 3:73's man. Gear's aren't terribly expensive and if you have the ambition to get it done then do it right the first time and go straight to 3:73's... You'll love it. Stick with Ford Racing or Richmond Gears. But if you really can't afford it then what the hell.... throw those 3:55's in her (They Will Fit). There Better then 3:08's.
Silver95Stint
New Member
IMO don't waste your time with 3.55's. Go to at least 3.73's, and you will drive until your heart's content.
gungfusemaj
Member
I went 3:08 to 3:73 with a stock 85 svo 5 speed 4 barrell carb and holy Crapsky I hardly used 1st gear unless it was some Rice burner thinking he could get on the Blu Oval..................2nd time was in my 87 gt from stock to 3:55 then :373 huge difference but the 2 questions should be are you using this car for a daily driver to and from work, on the highway etc, or do you have a 5spd or Aod. My 87 has a Aod with 3:73 and gt40 heads Trickflow manifold.....and let me tell you those gears really make a difference in your performance but also in you wallet for gas unless you have a Big Block. Because when you have those gears you WILL USE THEM AND ABUSE THEM. Exspecially on a Highway.....Good Luck ..........."
"I am the BigHam 
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"I am the BigHam and I approve this message"
I wouldnt screw with 3.73's if you already got the 3.55s. Its all a seat of the pants difference, no real performance gains. Most of the cars Ive beaten were 3.73 guys. Its all in the driver and your tires. So dont be fooled that you HAVE to have 3.73's or your car will be slow. Its far from true.
795.0pacecar
lover of pudgy polygamists
Just keep the 3.55s, I had 2.73s and put in the old 3.55s from my dads 03 mach 1 and it realy woke my car up, to me my car feels like a rocket and I still get good gas mileage, with me puttin my foot in it alot and driving on the highway alot I got 21 mpg something that for some reason I could never achieve with my 2.73s.
The used 3.55s will be noisy, I can attest to that, mine were very noisy so we set alittle more backlash in the pinion and it quieted down alot, and now it seems the more miles I put on it the quieter it gets so over all for some free gears, Im pretty happy.
Oh and before with my 2.73s when I hit 2nd gear under full throttle my tires would chirp alittle, now my car gets sideways.
The used 3.55s will be noisy, I can attest to that, mine were very noisy so we set alittle more backlash in the pinion and it quieted down alot, and now it seems the more miles I put on it the quieter it gets so over all for some free gears, Im pretty happy.
Oh and before with my 2.73s when I hit 2nd gear under full throttle my tires would chirp alittle, now my car gets sideways.
MustangMulch
New Member
I have 3.55s right now, but sometime soon i plan on switching to 3.73s or 3.90s (not sure which yet). You will like th 3.73s better than the 3.55s, but it's up to you if you wanna spend the extra money.
super302
I'd do anything for free Bapples
I got my 3.55's for free from my dads 'project' mustang 
, don't waste your money for a slightly taller gear, i've heard it's too much for a manual...like someone said, 1st gear will be worthless.
, don't waste your money for a slightly taller gear, i've heard it's too much for a manual...like someone said, 1st gear will be worthless.I went from 3.08 to 3.55 in my 5 speed. I feel the 3.55's are a great all-around ratio. I wish I had more gear around town, but less on the highway. I think 3.27's would be perfect for any appreciable amount of highway driving. My 3.55's keep me from driving as fast as I'd like on the freeway over long distances, due to concerns about my hearing and fuel consumption.
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