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onelozu
02-01-2012, 08:38 PM
anyone changing the gears in the rear end? im tired of pushing 3000-4000 rpms doing 60,id like to bring it down a bit

DroppedMitsu
02-01-2012, 09:55 PM
most trucks come with a 3.909 rear gear unless its a long bed/macro cab or auto, which came with a 3.545. Switch to a 3.545 and you'll drop the rpm probably just the amount your looking for.

Fordubishi
02-01-2012, 11:05 PM
Damn you're lucky. My stock rear gear was 4.13's or close to that. Now that the Ranger diff is in I have 3.45's and with the tranny in OD I turn 1700rpm at 110kph (around 70mph). before I changed it I would run around 4000rpm in OD. and the engine was 4600rpm redline (stock 85 302)

onelozu
02-02-2012, 09:15 AM
alright ill start looking,just got this one the other day and it reminded me of how much i hated the gearing in the green truck lol

lush90
02-05-2012, 10:30 AM
Damn you're lucky. My stock rear gear was 4.13's or close to that. Now that the Ranger diff is in I have 3.45's and with the tranny in OD I turn 1700rpm at 110kph (around 70mph). before I changed it I would run around 4000rpm in OD. and the engine was 4600rpm redline (stock 85 302)

What type of fuel mileage change did you get?

Fordubishi
02-05-2012, 11:56 AM
Around town I was getting 32-36mpg with a Holley 600cfm 4bbl if I stayed out of the 4bbl. On the highway I was getting 44-46mpg after a rebuild on the engine and going to the 85 Mustang HO cam.

originally with the 4.somethings I was getting just over 20mpg in the city and just under 30mpg on the highway. Got to love 145hp 180ft/lbs of torque on a 2200lbs truck. The 4's were fun I could roast tires all day but ran out of engine before 80mph and would be pushing red line across the 1/4 mile in 3rd.

1/4 mile times= with 4.what ever 15.91 @ 74mph, 60ft- 2.13 (average with traction)
with 3.45 posi 14.88@ 89mph, 60ft-2.28