4.27s in an LT4
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Instructor
Joined: Oct 2000
Posts: 221
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From: Austin, TX
4.27s in an LT4
Are 4.27 gears available for the rear differential that is stock on an LT4? My general plan for engine mods is to use a large cam and to have the motor built to rev up to ~6800. My first mod will be gears, in preparation for the loss of low end torque. Using this gear calculator:
http://www.f-body.org/gears/
4.27s with a ZF6 and 6800 rev limit works out these top speeds at the rev limit.
1st: 45
2nd: 68
3rd: 94
4th: 122
5th: 162
6th: 243
The top speeds in each gear are slightly higher than the top speed for each gear using 4.10s and the stock rev limit - 6400 - a combination a lot of people are using.
Given my plans for the motor, is there any reason not to go with 4.27s in the rear (if they exist)?
[Modified by Charles Klein, 5:09 PM 10/14/2001]
[Modified by Charles Klein, 5:10 PM 10/14/2001]
http://www.f-body.org/gears/
4.27s with a ZF6 and 6800 rev limit works out these top speeds at the rev limit.
1st: 45
2nd: 68
3rd: 94
4th: 122
5th: 162
6th: 243
The top speeds in each gear are slightly higher than the top speed for each gear using 4.10s and the stock rev limit - 6400 - a combination a lot of people are using.
Given my plans for the motor, is there any reason not to go with 4.27s in the rear (if they exist)?
[Modified by Charles Klein, 5:09 PM 10/14/2001]
[Modified by Charles Klein, 5:10 PM 10/14/2001]
Team Owner
Joined: Nov 1999
Posts: 32,782
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From: Former NCM Drag Racing coordinator, National director Corvette Challenge Spring Hill, Tennessee: Whiting, New Jersey
Cruise-In VI Veteran
Cruise-In VII Veteran
Re: 4.27s in an LT4 (Charles Klein)
I've been promoting to have someone try this combo for about 6 months.
4.27 gears with my wheel and tire combo in a 6m car and it should get real good 60'.
Go for it and let me know how you make out.
John
4.27 gears with my wheel and tire combo in a 6m car and it should get real good 60'.
Go for it and let me know how you make out.
John
Melting Slicks
Joined: Feb 2000
Posts: 3,299
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From: Beltsville Maryland
Re: 4.27s in an LT4 (Charles Klein)
I have run 4.27 gears in my 91 L98.This combo (26" tires) will push you through the finish line ~ 6550 rpm.That would work for your setup.The 4.27's pull hard in high gear.
Special note: I have a set to Super Dana 4.10's and 4.27's that I plan on selling in the near future.One of the sets will go with the D44 I also own.
Phil
Special note: I have a set to Super Dana 4.10's and 4.27's that I plan on selling in the near future.One of the sets will go with the D44 I also own.
Phil
