The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > All 4x4 Tech & Off Roading

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-18-2012, 03:52 AM   #1
Rifter_Chevy
Registered User
 
Join Date: Mar 2011
Location: Vancouver, Canada
Posts: 107
Gearing question

Here is the deal. I have a 84 4x4 pickup. I need rear end work done. I want to get a locker installed when i do the work.

However i also intend to lift and run larger tires so i want to change the gearing now, then lift later as i dont want to have to repurchase a locker when i lift(from what i understand the 3 series gears need a differnt locker than the 4 series).

Right now truck is sitting on 32x10.5 tires, has a TH 400 and a NP 208. I will be lifting and going with 36x10.5 tires and swapping out the 208 for a 205.

Currently i have 3.73 gears. I want to go to 4.56 gears when i do the rear end work, will also obviously swap the front axle gears at the same time.

How bad is the 4.56 gears going to be with my 32" tires. Will i even be able to drive on the highway?

Truck is a daily driver now but will not be after the lift, or at least not for very long after it. Truck is being built for a off road weekend toy.
__________________
1984 3/4 Ton Reg cab Longbox 4x4, Carbed 350/Turbo 400 Trans/205 T-Case
Rifter_Chevy is offline   Reply With Quote
Old 01-18-2012, 05:23 PM   #2
kwmech
Senior Member
 
Join Date: Mar 2003
Location: Colfax-California
Posts: 8,393
Re: Gearing question

That is roughly an 18% difference in gearing so your engine will be spinning that much faster. So if your 2500 at say 60mph. you will now be close to 3k at the same mph
kwmech is offline   Reply With Quote
Old 01-24-2012, 06:07 AM   #3
1malo68
Registered User
 
1malo68's Avatar
 
Join Date: Aug 2010
Location: Lost Wages, NV
Posts: 201
Re: Gearing question

This should answer all of your questions
http://www.grimmjeeper.com/gears.html
__________________
1968 K10/30
Frame Off Project "Overkill"
My 5 year, $30,000.00 toy
1malo68 is offline   Reply With Quote
Old 01-24-2012, 10:18 AM   #4
Chevy1TonFun
Grease Monkey
 
Chevy1TonFun's Avatar
 
Join Date: Oct 2007
Location: Fresno CA
Posts: 750
Re: Gearing question

I would lift the truck first then do gears. Your MPG is going to be pretty horrible with 32s and 4.56 gears.
__________________
Tow Rig: 2012 Chevy 2500HD CCSB LTZ Z71 4x4 Duramax
Ultimate Offroad Build: 1978 Chevy Silverado K30 Crewcab Build Link http://67-72chevytrucks.com/vboard/s...d.php?t=654053
Mud Truck: 1972 Chevy Cheyenne K30 4x4, 468/400/205, D60/D70HD, 18" Custom Lift, 17x39" IROKs
FOR SALE http://67-72chevytrucks.com/vboard/c...ton-4x4&cat=12
Chevy1TonFun is offline   Reply With Quote
Reply

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 11:23 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com