Best rear ratio
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Best rear ratio
I'm running 8.8/3.08 L diff. 83 302 with 35inch tires? is that the best set-up for mpg? Dont care about speed for the most part. Also it the 1984 351HO rare and does it look like the mustang 5.0?> Thanks
Post Fiend
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From: Louisiana
That gear ratio is way to low, I bet gas mileage is horrible in town.
I'm guessing it's a 4x4 with a rear Limited Slip.
I'd go with 4.10s to be safe, bring back the power, and bring up the mpgs.
Remember when you put gear oil in the diffs to put friction modifyer in with the Limited slip. If it's 4wd then regear front and rear diffs at the same time, and since your doing that you might think about lockers or a limited slip up front as well as the rear.
I'm guessing it's a 4x4 with a rear Limited Slip.
I'd go with 4.10s to be safe, bring back the power, and bring up the mpgs.
Remember when you put gear oil in the diffs to put friction modifyer in with the Limited slip. If it's 4wd then regear front and rear diffs at the same time, and since your doing that you might think about lockers or a limited slip up front as well as the rear.
Lead Driver
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From: Gateway to the West
I bet its got absolutely NO "giddyup" on hills and for passing. I ran 33's with 3.55's for a while and it sucked. Can't imagine what 35's with 3.08's must be like. Engine probably never reaches its powerband. With 35's you can go to 4.10's like MBB said or even 4.56's especially if you have a tranny with OD. This will allow youto go a little taller and not compromise your fuel mileage on the highway. Anything to help the bottom end when you are moving a 2.5 ton lump of Detroit steel will be beneficial. Keep in mind that when you regear both axles as MBB recommended, the ratios are not going to be identical. 4.10's for the 8.8 rear are going to translate to 4.09's for the Dana 44 front. Its a minor discrepancy that exists just because of the different manufacturers of the axles. The OEM gearing is actually 3.55 rear and 3.54 front.
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Yes, passing sucks right now i can not tell a difference when i step on it. Unless I hold it for around 5 minutes. I do have another Bronco in the back yard for parts its now wrecked. I'll take a look tomorrow what gear ratio its running? Its a 1985 inline 6. what could that be.
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Cargo Master
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From: Lynnwood, WA
Originally Posted by masseysbronco
i think trucks with the inline 6 got the 4.10 ratio, to help offset the lower engine power.
Post Fiend
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From: Louisiana
I didn't know Broncos came with any gear other than 3.55.
If they are 3.55 that would be an improvement over the 3.08s, but you would still want to go with at least 4.10s no matter what.
I'm going to put 4.10s(maybe 4.30) and 36" tires, but I'm going to be rebuilding my 400 for some nice power, so my engine won't have a problem with the little under gearing. I just don't wan to over gear, and bring the RPMs higher and the MPG lower.
I think 4.56 would be to high for a 302, C6 transmittion(I'm guessing), and 35" tires.
If they are 3.55 that would be an improvement over the 3.08s, but you would still want to go with at least 4.10s no matter what.
I'm going to put 4.10s(maybe 4.30) and 36" tires, but I'm going to be rebuilding my 400 for some nice power, so my engine won't have a problem with the little under gearing. I just don't wan to over gear, and bring the RPMs higher and the MPG lower.
I think 4.56 would be to high for a 302, C6 transmittion(I'm guessing), and 35" tires.
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From: Duncan,OK
Posting Guru
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From: Destin/Ft. Walton Beach,
That 0.01 difference is actually fully intentional to avoid the rear pushing the front.
Cargo Master
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From: Lynnwood, WA
I'm sorry if it doesn't make sense to you but that's the answer, and it's not related to manufacturing tolerances and differences. If you check front and rear ratios for compatible gear sets for Fords, in general, there will be about 0.01 difference between them with the front being lower (numerically) all the time.
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From: Indiana
I have read that the front and rear gears can be off as much as 1% before you tear anything up.
As for the gearing I would go with 4.56. Engine are designed to run in a certain rpm range anything out of that rpm range and the mileage go down. 4.56 should put you right back in the stock range.
As for the gearing I would go with 4.56. Engine are designed to run in a certain rpm range anything out of that rpm range and the mileage go down. 4.56 should put you right back in the stock range.
Last edited by Chris_ce; Sep 11, 2005 at 08:13 PM.