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 > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 11-02-2003, 07:15 PM   #1
Hotrodhenryj
Truck Farmer
 
Hotrodhenryj's Avatar
 
Join Date: Nov 2001
Location: Lake Havasu City, Arizona
Posts: 1,192
option code ?

Can anyone tell me the rear ratio with just option code. G80 is the code for the posi unit. Dont want to pull the cover unless it is necessary. Thanks
__________________
Arizona rust free sheetmetal
Hotrodhenryj is offline   Reply With Quote
Old 11-02-2003, 07:25 PM   #2
lukecp
Formerly yellow72custom
 
lukecp's Avatar
 
Join Date: May 2001
Location: Austin, TX
Posts: 7,531
On a 1/2 ton truck, models with a standard 6-cylinder (or small V8, 283/307) engine usually had factory 3.73 gears. 350/327/396/402 equipped trucks usually had 3.07 gears.
__________________
'72 Chevy C10 Mild 350/TH350/3.07. Ochre/White. Old high school ride.
'70 GMC C2500 '62 327 4bbl/SM465/4.56-geared Dana 60. White/White. Project or parts truck.
'97 Saturn SL DD. 1.9/5-speed. 40+ highway mpg
lukecp is offline   Reply With Quote
Old 11-02-2003, 07:27 PM   #3
Rod
 
Join Date: Dec 1999
Location: Eastern - Manitoba Canada, Winnipeg
Posts: 4,369
Its not that easy to tell but... if this is what you want here it is for 1/2 tons.

H01 is 3.07
H05 is 3.73
H04 is 4.11

If you dont have any option code listed it probably has the standard equipment... most like if it s a 6 cyl it's 3.73 if its an original 8 it's more than likely 3.07
__________________
Senior active founding member.
70 3/4 ton GMC Suburban 4x4 250/4 spd.
71 1/2 ton Suburban Chevy 4x4, 350/350
72 Chev 1 ton tow truck 402BB w/Holmes 440 wrecker on propane
2005 FLSTSCI Harley Springer
85 FXSB Harley Lowrider
72 Triumph 650 Bonneville 5spd
"Poor people don't have hobbies" Quote from wife.
Rod is offline   Reply With Quote
Old 11-02-2003, 09:36 PM   #4
Hotrodhenryj
Truck Farmer
 
Hotrodhenryj's Avatar
 
Join Date: Nov 2001
Location: Lake Havasu City, Arizona
Posts: 1,192
OK, this is a 1/2 with factory installed 350. I was hoping the option code G80 on the glove box sticker was a clue for the ratio. Guess it just means positraction rear.

Rod, Those numbers you gave are they the ones on the id tag on the rear housing?
Thanks guys.
__________________
Arizona rust free sheetmetal
Hotrodhenryj is offline   Reply With Quote
Old 11-03-2003, 11:19 AM   #5
Paul72
Registered User
 
Paul72's Avatar
 
Join Date: Sep 2003
Location: Waterloo, IA
Posts: 1,147
Jack up the rear end and put a mark on the drive shaft. Turn the right rear tire 1 revolution (if you have a posi) or 2 revolutions (for an open) and count the drive shaft revolutions. This will get you in the ball park.

Paul
__________________
'72 Chevy K20 - 383/4sp/205 - SOLD after 41 years in the family
Next project - K/5 Tahoe (71 Blazer on 99 Tahoe chassis) Build thread: http://67-72chevytrucks.com/vboard/s...d.php?t=789958
Paul72 is offline   Reply With Quote
Old 11-03-2003, 12:18 PM   #6
cableguy0
Senior Member
 
Join Date: Apr 2000
Location: Delta,Pa
Posts: 14,950
if its an original 350 truck i will bet it has 3.07's if not it would have the optioned listed for 3.73 gears.
__________________
Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.
cableguy0 is offline   Reply With Quote
Old 11-03-2003, 02:01 PM   #7
Classic Heartbeat
Project Junkie! Fishing Poor!!
 
Classic Heartbeat's Avatar
 
Join Date: Dec 1999
Location: Olympia,Wa. 98512
Posts: 10,770
There is a series of numbers on the top right hand side of the axle. The first 3 letters will be the numbers that you need to decifer the gear ratio and wether or not it is a possi. WES www.ClassicHeartbeat.com
__________________
On-line catolog
Classic Heartbeat Pickup Parts
WEHEPP@comcast.net
Call us Toll Free (888) 338-2502
Like Us on Facebook
No appointment necessary.
72 BB Chevy Custom Deluxe / Custom Camper
67 I-6 (Soon to be 5.7 LS1) Panel
68 BB Chevy Short Bed
72 6.0 LQ9 Short Bed Chevy 4X4
Olympia's fastest growing truck parts supplier.
Olympia's home for Wayward Chevys
Classic Heartbeat is offline   Reply With Quote
Old 08-28-2015, 05:09 PM   #8
DangerDan
Registered User
 
Join Date: Aug 2015
Location: Fort Wayne, IN
Posts: 39
Re: option code ?

Who was the manufacturer of these axles? My 6 Cyl. Has the G80 code as well thanks for the info!
DangerDan is offline   Reply With Quote
Old 08-28-2015, 05:40 PM   #9
68350
Senior Member
 
68350's Avatar
 
Join Date: Jan 2002
Location: Williston, ND
Posts: 2,999
Re: option code ?

GM build the 12 bolts. They weren't outsources. Was the original posters truck a 4 speed or automatic transmission?
__________________
68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets
68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction
69 Chevy Camaro SS, 383, 4 speed, positraction
70 Chevy El Camino SS396, Triple Black, 454/th400, Tach
70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks
70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR
71 Chevy Blazer, CST, 350/auto
71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s
71 Custom/30, Open Road, 350/th400, tilt
72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi
72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi
68350 is offline   Reply With Quote
Old 08-28-2015, 06:27 PM   #10
Bigdav160
Registered User
 
Bigdav160's Avatar
 
Join Date: Apr 2011
Location: Klein Texas
Posts: 3,852
Re: option code ?

But the OE positraction units were.......Spicer? Ugh, I can't remember.
__________________
My Classics:
'72 K20 Suburban + '65 Dodge Town Wagon
'72 Corvette Roadster +'67 Corvette Roadster
'73 Z-28 Camaro
'63 Ford SWB Uni Pickup
'50 Ford Coupe
Bigdav160 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 06:42 PM.


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