Transmissions and Drivetrain Need help with your trans? Problems with your axle?

2.73 to 3.42 swap a couple of questions

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Old Jul 19, 2020 | 11:49 AM
  #1  
George Klass's Avatar
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From: Montreal
Car: 1989 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 3.42
2.73 to 3.42 swap a couple of questions

I'm installing a new Yukon posi and 3.42 gears this week. 1989 TBI with 700R4

Instead of changing the speedo gears
can I use a Dakota Digital box instead?

I was also told I need to swap out the governor for one from a 3.42 car?


Last edited by George Klass; Jul 19, 2020 at 03:42 PM.
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Old Jul 19, 2020 | 04:55 PM
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From: Chasing Electrons
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Transmission: check
Re: 2.73 to 3.42 swap a couple of questions

Yes, an '89 Firebird should be using a 4K PPM magnetic sensor along with a 4-OUT BUFFER box. Replace that box with the Dakota Digital box.

As for the governor, yes it is possible that you may want to replace it. But give the stock one a go first. A V6 governor is probably going to shift at a higher MPH then a V8 governor.

RBob.


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Old Jul 19, 2020 | 05:20 PM
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Car: 1984 Camaro Berlinetta
Engine: LT1
Transmission: T56 6-speed
Axle/Gears: 4.11 LS1 Rear End
Re: 2.73 to 3.42 swap a couple of questions

Rob has you covered,........... YES to the signal converter and YES to the Governor !


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Old Jul 19, 2020 | 05:39 PM
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From: Western Pa
Car: 1989 Trans Am
Engine: 305 H.O. TPI
Transmission: Auto 700R4
Axle/Gears: 3.42 posi
Re: 2.73 to 3.42 swap a couple of questions

Originally Posted by RBob
Yes, an '89 Firebird should be using a 4K PPM magnetic sensor along with a 4-OUT BUFFER box. Replace that box with the Dakota Digital box.

As for the governor, yes it is possible that you may want to replace it. But give the stock one a go first. A V6 governor is probably going to shift at a higher MPH then a V8 governor.

RBob.
Not wanting to hijack the thread but you seem to know a bit about this, I have an 89 T/A that was 2.73 gears and is now 3.42s, speedo is way off, what box do I need from Dakota Digital? Thanks in advance!
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Old Jul 19, 2020 | 07:17 PM
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George Klass's Avatar
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From: Montreal
Car: 1989 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 3.42
Re: 2.73 to 3.42 swap a couple of questions

Thanks guys! I've been looking for a V6 governor but they seem to be hard to find.

Kincer this is it

https://www.summitracing.com/parts/dak-sgi-100bt
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Old Jul 20, 2020 | 07:41 AM
  #6  
George Klass's Avatar
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From: Montreal
Car: 1989 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 3.42
Re: 2.73 to 3.42 swap a couple of questions

Ordered the converter should be here soon I hope. Diff is going back on the car this weekend so might have a funky speedo for a few days haha.
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Old Jul 20, 2020 | 11:58 AM
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Car: 1990 Pontiac Firebird Formula
Engine: L31 350 TPI
Transmission: Tremec TKX
Axle/Gears: 3.23 Posi
Re: 2.73 to 3.42 swap a couple of questions

Just my experience: I swapped 2.73 for 3.23 in my (originally LO3/700R4) Formula. WOT 1-2 shifted at 4,200 rpm; 2-3 at 4,000 rpm. I pulled the governor and swapped in a lighter weight and got the WOT shifts back up to ~5,000 rpm. If you shift it manually, this isn't a concern. A V6 governor will probably give you shifts in the 6,000+ range.
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Old Jul 20, 2020 | 12:10 PM
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George Klass's Avatar
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From: Montreal
Car: 1989 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 3.42
Re: 2.73 to 3.42 swap a couple of questions

Good to know. I'm to try it with the stock one for now. I don't really rip this car at all so if regular driving stays the same I'm good until I find the right governor.
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Old Jul 20, 2020 | 03:18 PM
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Kincer's Avatar
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From: Western Pa
Car: 1989 Trans Am
Engine: 305 H.O. TPI
Transmission: Auto 700R4
Axle/Gears: 3.42 posi
Re: 2.73 to 3.42 swap a couple of questions

Originally Posted by George Klass
Thanks guys! I've been looking for a V6 governor but they seem to be hard to find.

Kincer this is it

https://www.summitracing.com/parts/dak-sgi-100bt
Thank you!
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Old Jul 21, 2020 | 09:22 AM
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Car: 1991 Z28
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 3:42 Auburn
Re: 2.73 to 3.42 swap a couple of questions

Originally Posted by George Klass
Thanks guys! I've been looking for a V6 governor but they seem to be hard to find.

Kincer this is it

https://www.summitracing.com/parts/dak-sgi-100bt
Do you guys know if this works for the Camaro also? I too have 3:42 gears with larger than stock rear tires.
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Old Jul 21, 2020 | 01:32 PM
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From: Montreal
Car: 1989 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 3.42
Re: 2.73 to 3.42 swap a couple of questions

If your car has a electric speedo I think it should?
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Old Jul 24, 2020 | 07:07 AM
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From: Duluth, Ga
Car: 91 RS
Engine: 305 TPI
Transmission: T56
Axle/Gears: Auburn Pro / 3.42
Re: 2.73 to 3.42 swap a couple of questions

Originally Posted by vinny R
Do you guys know if this works for the Camaro also? I too have 3:42 gears with larger than stock rear tires.
The 90-92 Camaro came with a digital speedo so this will work.
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Old Jul 24, 2020 | 08:33 AM
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Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Re: 2.73 to 3.42 swap a couple of questions

I need to find a governor to make mine shift 5200-5500. With the L03 4500rpm shifts are fine where mine is and I can shift it manually where I want but when my new engine goes in I think 5500 would be optimal but I sure don't want a V6 governor to pull it to 6000rpms. Can anyone suggest the right governor?
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Old Jul 25, 2020 | 08:05 PM
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Car: 1988 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 10 Bolt 2.73 Open
Re: 2.73 to 3.42 swap a couple of questions

Subscribed.
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Old Jul 26, 2020 | 07:11 AM
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From: Florida
Car: 1991 Z28
Engine: 305 TPI
Transmission: 700R4
Axle/Gears: 3:42 Auburn
Re: 2.73 to 3.42 swap a couple of questions

Originally Posted by dmccain
I need to find a governor to make mine shift 5200-5500. With the L03 4500rpm shifts are fine where mine is and I can shift it manually where I want but when my new engine goes in I think 5500 would be optimal but I sure don't want a V6 governor to pull it to 6000rpms. Can anyone suggest the right governor?
B&M makes a kit. It comes with springs and weights to adjust the shift point that will fit your needs.
https://www.jegs.com/i/B-M/130/20248/10002/-1
I am not 100% but is the governor part of the shift servo? If that is the case you want the corvette shift servo.
https://globaltransmissionparts.com/...y-700r4-4l60e/
You may want to use both as the servo firms up the shifts between gears and use the kit to adjust the RPM of the shifts.
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Old Jul 27, 2020 | 07:17 AM
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From: South Ms
Car: 89 Firebird
Engine: 355 TBI
Transmission: 700R4
Axle/Gears: 10 Bolt.Posi-3.73s
Re: 2.73 to 3.42 swap a couple of questions

Originally Posted by vinny R
B&M makes a kit. It comes with springs and weights to adjust the shift point that will fit your needs.
https://www.jegs.com/i/B-M/130/20248/10002/-1
I am not 100% but is the governor part of the shift servo? If that is the case you want the corvette shift servo.
https://globaltransmissionparts.com/...y-700r4-4l60e/
You may want to use both as the servo firms up the shifts between gears and use the kit to adjust the RPM of the shifts.
Thanks Vinny I will be ordering it. My transmission shifts hard enough to knock your teeth out under WOT right now when I had it rebuilt it got a shift kit, but when I drop this L98 in there I definitely don't want WOT shifts @ 4500.
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Old Jul 27, 2020 | 07:32 AM
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From: Montreal
Car: 1989 Trans Am
Engine: L03
Transmission: 700R4
Axle/Gears: 3.42
Re: 2.73 to 3.42 swap a couple of questions

I feel like with that kit will take forever to get right. Maybe just use a governor from an L98 car?
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Old Jul 27, 2020 | 02:19 PM
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Car: 1991 Z28
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Transmission: 700R4
Axle/Gears: 3:42 Auburn
Re: 2.73 to 3.42 swap a couple of questions

Originally Posted by George Klass
I feel like with that kit will take forever to get right. Maybe just use a governor from an L98 car?
I would hope they put some sort of instructions/guide in the kit so it is not like just taking a stab at it.
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