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1965 Ford Mustang
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Hi i have a 65 mustang, soon there will be a 302 and c4 tranny(all stock). what gears should i run in the diff. i bought a 8 inch 66 diff that has 2.88 gears. i plan on it just being a cruiser
 

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The rear it has will do just fine with great MPG and highway rpm. We have 3 with 2.80 gears at home and they Giddy-up just fine!
 

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For just a cruiser without an overdrive transmission, just leave as is. Now if you were putting in a T5 transmission I'd change it to a 3.4 or a 3.55. My T5 has a 5th gear ratio of 0.63 and a 3.4 diff. Works great.
 

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The differential is the center part with the ring & pinion and the spider gears. The individual axles are rear axles. The entire assembly in the housing is a rear end.
If you're only cruising up and down Main Street in front of the Dairy Queen or Sonic 3.40 or 3.55 gears will give you lots of get up and go when you nail the gas pedal. If you occasionally get on the highway 3.25 or 3.40 gears will be good. If you do lots of highway driving 3.00 or 3.25 gears are good. The difference between 2.80 and 3.00 is slight and maybe not worth it unless somebody gives you the gears.
 

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If it's a cruiser, and you have no intentions of doing any performance stuff, leave it as is..2:88's are fine.
 

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65 Fastback 289 4 spd, 65 convertible 5.0L 5 spd. 3.73 8.8
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Hi i have a 65 mustang, soon there will be a 302 and c4 tranny(all stock). what gears should i run in the diff. i bought a 8 inch 66 diff that has 2.88 gears. i plan on it just being a cruiser
Agree with other responses, I would go to a 3.25 but no lower. I have 2.80 in one car with a 289 4spd. the other I have is a 5.0L, T5 with 3.73, which works great, but wouldn't want to go any lower.
 

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leave it as it is, if you think you might wanna change it, drive down the highway in 2nd gear and see how much you like it. Is the extra acceleration worth the high revs? Only you can decide.
 

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Agree with other responses, I would go to a 3.25 but no lower. I have 2.80 in one car with a 289 4spd. the other I have is a 5.0L, T5 with 3.73, which works great, but wouldn't want to go any lower.
Matt,
High numbers are Low Gears, just to be clear. This throws many people off.
 
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