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#1 |
Registered User
Join Date: Jan 2005
Location: Central CA
Posts: 86
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G80 differential
I have replaced the motor, tranny, and driveline in my 70 C-10, trying to upgrade things as I go. The only thing that remains of the original drivetrain is the rear-end. The glove-box sticker says it is a G80 positrac axle, does anyone know anything about this rear-end? Did they come in any particular ratio? Are they a solid rear-end? If so I will just keep it in place unless it gives me any trouble.
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#2 |
Registered User
Join Date: Oct 2003
Location: Carmichael, California
Posts: 3,006
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it should be a 12 bolt posi. G80 is just the GM code for it. They are strong enough and could have several different ratios. It might say on your glove box sticker what ratio it should be if it`s the original rearend.
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Anthony |
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#3 |
70+ ( Old Skool Club )
![]() Join Date: Nov 2003
Location: Saskatoon, Saskatchewan ,Canada
Posts: 9,119
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Ratios
If you have the GU4 Code its a 3:08 , GU5- 3:23, GU6-3:42, .. I wrecked an 85 Burb and it had the GT4 code which stated it was a 3:73... Hope I helped..
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1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021 |
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#4 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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Where did these come from?
There was no 3.23 nor 3.42 gear sets avalible 67 - 72. |
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#5 |
70+ ( Old Skool Club )
![]() Join Date: Nov 2003
Location: Saskatoon, Saskatchewan ,Canada
Posts: 9,119
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From
From 80's Suburbans ,I just assumed that GM like Chrysler ( where I worked for 25 years) have used the same codes forever.
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1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021 |
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#6 |
70+ ( Old Skool Club )
![]() Join Date: Nov 2003
Location: Saskatoon, Saskatchewan ,Canada
Posts: 9,119
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Mmmm!!!
So Longhorn what you are saying is that the 67/72 Trucks came with 3:73 gears, or lower ratios? On another thread you were talking about the GM Info Packet. I got that specifically for my truck and I stil haven't found what ratio my 350/Turbo350 truck came with . I do know its a 12bolt (cause I counted them, lol) non-posi Rear end.
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1972 C10 Custom/Deluxe 613 Highlander 406/700R4 1999 White Tahoe LS 4x2 with Z56 Police Package 1992 K1500 GMC Suburban Members I have personally met: MusicMan70 - HeavyD - ChewyChevy67 - StingRay -71SWB4x4 - 67 Burb - DeadheadNM - too much stuff - bc65 - das601 " Circumsatances Do Not Change Responsibility " " The Sky is not the Limit, Your Mind is." Marilyn Monroe .. RIP Charlie Watts 1941 - 2021 |
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#7 |
Watch out for your cornhole !
![]() Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
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3.08 is also common on V8 half ton trucks too.
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I'm on the Instagram- @Gearhead_Kevin |
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#8 |
its all about the +6 inches
Join Date: Jan 2001
Location: Hilliard Ohio
Posts: 2,693
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in 1/2 ton 67 - 72 trucks, there was 4.11 (maybe 4.10, can never remember) 3.73 and 3.07
In most of the 3/4 ton and one tons, they were 4.11 (or 4.10...again, get them flip flopped all the time) and 4.56. I mqay be wrong on this...but I think the big blocks (both 1/2 ton and 3/4 ton) got 3.56 gears...or something like that. |
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