3.55 or 3.73's?

I have an 89 GT vert AOD. After installing Flows and BBK h pipe, I really noticed loss of low end torque. Someone suggested changing the rear end gear to a 3.55. I guess right now it has a 2.73. I think I will make a change, but should I go 3.55, or 3.73? I don't do very much highway driving with this car. Much of my driving is around town, Not usually over 60 MPH. Any suggestions? Pros? Cons? Any idea about cost? I'm thinking somewhere around $500.00. Is that about right? Thanks, Howard

Reply to
Howard Mora
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With an AOD I would go either 3.73 or 4.10, I dont do any highway driving and I'll be going 4.10's this summer.

Reply to
John Wiebalk

"Howard Mora" wrote in news:Ax7lc.508235$ snipped-for-privacy@twister.tampabay.rr.com:

With an AOD, you've got to go to 3.73s. That's my setup and I'm very happy with it. There's a _lot_ more pull down low because of the numerically high ratio, but it'll still cruise very happily at 85mph. Don't know about costs these days, as I did mine years ago.

At any rate, you might still have to do something on the intake side to counter the h-pipe effect. Gears will certainly help, but you still have an "unbalanced" air in/out ratio. You've affected the exhaust without considering the intake. Look into a bigger MAF and an intake. HTH.

Joe Calypso Green '93 5.0 LX AOD hatch with a few goodies Black '03 Dakota 5.9 R/T CC

Reply to
Joe

I agree with Joe. I have 3.70s in my AOD Maverick and I like the way it feels. I've used 3.50s behind AODs with pleasant results and would not be afraid to go with 3.25s if HWY fuel economy was my main concern.

C8oe

Reply to
W3tac8oe

Howard,

Here's how you find out what gears your car came with from the factory. Check the sticker on the inside driver's side door jam. Look at the axle code block on this sticker.

Axle codes M = 2.73s Z = 3.08s E = 3.27s

Here are my recomendations for gears:

- On your heavy convertible/automatic transmission, I'd opt for 3.73s or 4.10s.

- If it's just going to be a street car, go with the 3.73s.

- However, if it's going to be dual use -- street/strip car -- go with the 4.10s.

- Along with the gear change, change your transmission fluid and install a trans cooler and shift kit.

Gears cost about 175 bucks. Installation costs range from about $125

- $250. Make sure you get a competent person/shop to do the install!

Hope this helps. Good luck.

Patrick '93 Cobra '83 LTD

Reply to
Patrick

Go with 3.73s.

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Reply to
Katmandu

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