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3.42's or 3.73's??

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Old Feb 20, 2004 | 12:12 AM
  #1  
ThirdGenFire's Avatar
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From: El Paso, Texas
Car: 2000 Trans Am and a 85 Iroc-Z
Engine: The Mighty LS1& 305 just beat meTPI
Transmission: 4L60E and 700R4
3.42's or 3.73's??

I will be adding a ported set of heads this week hopefully and I was thinking of getting some gears in to replace my 3.23's. The 3.42 jump doesn't seem like much to me and the 3.73's seem like they would work better. I do a lot of driving but milage is not an issue to me as it is bad anyway. I am also getting a 2500 stall converter as well in the coming weeks. So if that helps. What do you all think would benifit me more the 3.42's or the 3.73's? Thanks.
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Old Feb 20, 2004 | 12:48 AM
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Car: NCC-1701-D (docked in AZ)
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Axle/Gears: Rescued from the Borg by my crew
Re: 3.42's or 3.73's??

Originally posted by ThirdGenFire
I will be adding a ported set of heads this week hopefully and I was thinking of getting some gears in to replace my 3.23's. The 3.42 jump doesn't seem like much to me and the 3.73's seem like they would work better. I do a lot of driving but milage is not an issue to me as it is bad anyway. I am also getting a 2500 stall converter as well in the coming weeks. So if that helps. What do you all think would benifit me more the 3.42's or the 3.73's? Thanks.
With the 2500 stall...3.73's
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Old Feb 20, 2004 | 11:03 AM
  #3  
ThirdGenFire's Avatar
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From: El Paso, Texas
Car: 2000 Trans Am and a 85 Iroc-Z
Engine: The Mighty LS1& 305 just beat meTPI
Transmission: 4L60E and 700R4
Thats what I was thinking as well. I am adding that high stall converter and the 3.73's seem like they would work rather well in this combo. I wanna try and stay in the meat of the TPI band. I just wanna get a good enough launch to stay ahead long enough. Thank you for answering.
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Old Feb 20, 2004 | 12:04 PM
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screamin' 85 z's Avatar
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From: Durham NC
Car: 85 IROC
Engine: 355 CI n/a
Transmission: 700 r4 w/3500 Coan
Went both routes when mine was TPI...If you want to stay in your powerband, 3.42's are the way to go..I lost almost 2 tenths with 3.73's the TPI more than compensates with its torque. Also if you ever plan on spraying, 3.42's will keep you out of redline in the quarter..
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Old Feb 20, 2004 | 02:57 PM
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Car: NCC-1701-D (docked in AZ)
Engine: impulse drive
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3.73's...
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Old Feb 20, 2004 | 04:02 PM
  #6  
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From: Manati, PR
Car: Trans Am "GTA"
Engine: 305 TPI
Transmission: Auto
whats the best stall to mathc a 3.42's?
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Old Feb 20, 2004 | 04:05 PM
  #7  
D Stroy H8's Avatar
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From: Las Vegas, NV
Car: 1990 Iroc-Z
Engine: L98
Transmission: 700R4
I would go with the 3.42s

The TPI low end, and that stall converter will launch you HARD. The 3.42s will maintain a really nice acceleration, while not topping you out too soon (keeping you in the powerband LONGER)

3.42s!!!
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Old Feb 20, 2004 | 05:40 PM
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ThirdGenFire's Avatar
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From: El Paso, Texas
Car: 2000 Trans Am and a 85 Iroc-Z
Engine: The Mighty LS1& 305 just beat meTPI
Transmission: 4L60E and 700R4
Damn mixed reactions huh. Now I am confused.
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Old Feb 21, 2004 | 12:35 AM
  #9  
OMINOUS_87's Avatar
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From: Mesa, AZ: Transplanted from Chicago, IL
Bottom line, 3.42.

The only reson to run more gear on a TPI motor was if you were planning to drive taller tires, such as a 27" or 28" slick at the track.

For the street 3.42 is what you want, 3.73 will not be your best street option. The converter you have is fine, dont change it.
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Old Feb 21, 2004 | 02:04 AM
  #10  
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From: Houston
Car: C-20
Engine: 260 boat anchor Mexican 350 (crate) TPI (MAF)
Transmission: THM-400 I turn 3500 (which is where my pos engine's power starts droping off) at 80 I need a 4L80-E
you should put in your 2500 stall converter and then decide if you want to change your ratio.
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Old Feb 21, 2004 | 09:29 AM
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screamin' 85 z's Avatar
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From: Durham NC
Car: 85 IROC
Engine: 355 CI n/a
Transmission: 700 r4 w/3500 Coan
Remember: TPI motors are rich in torque: Don't out-stall your powerband..2800-3000 is plenty with 3.42's
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