Recomendations for Differential gears
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Joined: Jun 2006
Posts: 57
Likes: 0
From: Irvine California
Recomendations for Differential gears
81 currently with 4 spd stock trans, stock differential in CA. Looking to get some recommendations on what gear ratio would work best to upgrade to. Looking for good intown driving but need to be able to get on the I-5 highway. If you now CA, what to be able to keep up with the flow of traffic (80 or so) for 40min + and not run at 3k rpm the entire time.
Drifting
Joined: Sep 2006
Posts: 1,259
Likes: 2
From: MS
The 2.72 should put you at 2700 rpm at 80 mph, if you are turning more revs somebody
must have swapped your gears to something lower.
Safety Car
Joined: Nov 2004
Posts: 4,359
Likes: 57
From: Mundelein Illinois
If you have the stock 2:72 leave it alone. It is an all around good gear for the trans.
I went to 3:55 engine was screaming on the expressway no bad at 45mph and under.
Switched back to the 2:72
Then replaced trans with tremic 5 speed from Keisler and changed rear end gear to 3:55 and this set up is perfect.
In short leave it alone unless your going to put a 5 speed in it. Don't go through what I did.
I went to 3:55 engine was screaming on the expressway no bad at 45mph and under.
Switched back to the 2:72
Then replaced trans with tremic 5 speed from Keisler and changed rear end gear to 3:55 and this set up is perfect.
In short leave it alone unless your going to put a 5 speed in it. Don't go through what I did.
Drifting
Joined: Apr 2008
Posts: 1,305
Likes: 2
From: Lewisburg WV
thegazman
Alan.....I have a 79 L82 with a 350 automatic and 3:70 differential. It's great around town, but it runs between 3500-4000 rpm on the interstate (freeway to you). At higher speeds the engine is reved up and noisey. Spedaleden is correct....unless you can afford an overdrive trans, leave the diferential alone. Plus, if you lower your differential ratio you're going to experience a sharp drop in your fuel mileage. I average approximately 11 mpg around town and 13 mpg on a trip.
