Which gears?

U

u0061914

New Member

Aug 20, 2009

54

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Prior Lake, MN

Sep 11, 2009

#1

• Sep 11, 2009

• #1

I have started my I6 to v8 conversion this week. In the process found a fairly built 289 (cam and some headwork) with an AOD which was in another 67. I also picked up a 9" from a 69 Mach 1. The 9" alegedly has 3.00 gears in it. I also have a 9" 3rd member with 3.50 gears in my parts shed. With my setup, which are the preferable gears? I'm tinking that the 3.50s might be better with the overdrive. Any thoughts?

 

2

2+2GT

10 Year Member

Apr 25, 2009

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Southeastern Pennsylvania

Sep 11, 2009

#2

• Sep 11, 2009

• #2

Absolutely use the 3.50.

 

golf4283

Active Member

May 30, 2003

1,253

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39

Orland Park, Illinois

Sep 11, 2009

#3

• Sep 11, 2009

• #3

^^^ What he said. With that overdrive gear you'd be dumb not to go with a higher rear end ration.

 

mr408

New Member

Aug 20, 2009

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australia

Sep 13, 2009

#4

• Sep 13, 2009

• #4

Yep , go the 3.50 , you still will only be doing about 2000rpm in overdrive with 3.50 at 60mph, depending on your wheel and tyre diameter.

 

68stang351

Founding Member

May 16, 2002

850

9

39

Savoy TX

Sep 13, 2009

#5

• Sep 13, 2009

• #5

3.50.

You wont like it with 3.00's in it.

 

armand67Fstback

Member

Oct 30, 2007

146

1

19

Sep 13, 2009

#6

• Sep 13, 2009

• #6

Another vote for the 3.50s here.

 

rbohm

Founding Member

Apr 12, 2002

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204

tucson,az

Sep 13, 2009

#7

• Sep 13, 2009

• #7

one more vote for the 3.50's

 

65ShelbyClone

Founding Member

Sep 9, 2000

4,675

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119

Antelope Valley, SoCal

Sep 13, 2009

#8

• Sep 13, 2009

• #8

+1 for 3.50s.

 

calpolymustang

Member

Feb 1, 2004

217

0

16

Santa Rosa, CA

Sep 13, 2009

#9

• Sep 13, 2009

• #9

I had a 3.40, but it seemed to be running a little too low with my 25.2" tires and .67 overdrive gear.

Now I have 4.11s, and ZERO regret. At 65mph, I'm spinning 2300; at 75, 2600rpm.
The response of the car taking off from a stop is much better. Keep in mind 1st gear is only 2.46:1

 

tx65coupe

Active Member

Nov 29, 1999

1,551

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37

Sep 13, 2009

#10

• Sep 13, 2009

• #10

With overdrive definitely the 3.50 gears over the 3.00 gears.

 

5

57fairlane

New Member

Apr 2, 2005

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Oakwood, GA

Sep 13, 2009

#11

• Sep 13, 2009

• #11

3.50, but you could easily go with more gear.

 

6Stang7

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Jun 1, 2003

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Livermore, CA

Sep 14, 2009

#12

• Sep 14, 2009

• #12

57fairlane said:

3.50, but you could easily go with more gear.

Click to expand...

He speaks the truth. I have 4.11's in the 67 and I run around 2k on the freeway. Get the 3.5's.

 

RGS0907

New Member

Aug 21, 2003

429

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New Jersey

Sep 14, 2009

#13

• Sep 14, 2009

• #13

calpolymustang said:

I had a 3.40, but it seemed to be running a little too low with my 25.2" tires and .67 overdrive gear.

Now I have 4.11s, and ZERO regret. At 65mph, I'm spinning 2300; at 75, 2600rpm.
The response of the car taking off from a stop is much better. Keep in mind 1st gear is only 2.46:1

Click to expand...

4:11s have a way of making you smile

 

U

u0061914

New Member

Aug 20, 2009

54

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0

Prior Lake, MN

Sep 14, 2009

#14

• Sep 14, 2009

• #14

Thanks all. I'm now thinking that I may skip both and regear to 3.73 or 4.11s. They way the money is flowing into this project, what's the cost of a ring/pinion, etc!

 

blown65

Founding Member

Jul 7, 1999

1,938

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39

Queen Creek Arizona

Sep 14, 2009

#15

• Sep 14, 2009

• #15

I'd go no lower than 4.11's. Even with 4.56 gears and the AOD your looking at 2500 rpm at 65-70mph anyways. Just depends on the rest of the combo, but I love the 4.56's/AOD combo in the Shelby.

3.0 or 3.50's, no thanks.