What rear end? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bkkpool · 12-19-2012, 09:50 PM

Can anyone tell me what rear end is in this truck from the SPID?

Posted via Mobile Device
Posted via Mobile Device

Tinkermc · 12-19-2012, 09:52 PM

I may be wrong but to my knowledge no

GASoline71 · 12-20-2012, 12:21 AM

I'm gonna take a swing and say a 12 bolt...

***Unless it's a 3/4 ton... and it might be an Eaton or a Dana***
Gary

dan42 · 12-20-2012, 12:24 AM

It's a half ton, and I believe the standard rear end was probably a 3 .73 12 bolt.
Posted via Mobile Device

**Already Gone** · 12-20-2012, 12:58 AM

Unless it shows something specific on the spid, i'm pretty sure big blocks with automatics came with a 3:08 Ratio.
Posted via Mobile Device

bkkpool · 12-20-2012, 01:00 AM

Will it be an open or limited slip in a BB truck?
Posted via Mobile Device

GASoline71 · 12-20-2012, 01:08 AM

Could be either.

Gary

**Already Gone** · 12-20-2012, 01:22 AM

I am 99% sure if the truck came with Limited-Slip Positraction it was an option so it'd be on the spid. Are you sure the original rearvend is in your truck?
Posted via Mobile Device

bkkpool · 12-20-2012, 01:41 AM

I'm fairly confident it is the original rear end. I'm considering buying it for parts and to part out. Unfortunately the motor was swapped 20+ years ago. I may go see the truck this weekend.
Posted via Mobile Device

SS Tim · 12-20-2012, 04:23 AM

Chevy 3500lb axle (AKA 12 bolt). 3.07 gears with no listed option except open or posi..

bkkpool · 12-20-2012, 11:00 AM

It appears that it is an open 3.07.Thanks for the info.

IHeartGroceries · 12-20-2012, 11:30 AM

The SPID on my truck (350/350) doesn't list any particulars about the rear end.
So, from what you guys are saying, it is safe to assume it uses standard eqipment (3.07).

However, there is no way the rear end has 3.07 in it. It is wound like a top at 60MPH. It is nearly unbearable. I don't have a tach, but I'd estimate 3500 RPM @ 60 MPH.

Any ideas? At what RPM should 3.07 be @ 60 MPH?

I might as well just yank the cover and look in the case. It has started dropping oil anyway.

1972SUPERSB · 12-20-2012, 12:22 PM

Quote:

Originally Posted by IHeartGroceries

The SPID on my truck (350/350) doesn't list any particulars about the rear end.
So, from what you guys are saying, it is safe to assume it uses standard eqipment (3.07).

However, there is no way the rear end has 3.07 in it. It is wound like a top at 60MPH. It is nearly unbearable. I don't have a tach, but I'd estimate 3500 RPM @ 60 MPH.

Any ideas? At what RPM should 3.07 be @ 60 MPH?

I might as well just yank the cover and look in the case. It has started dropping oil anyway.

Prob had some lower gears installed in it at some time. If I would guess you should be around 2400 rpm or so with 3.07 also depending on what you tire size is.
Posted via Mobile Device

IHeartGroceries · 12-20-2012, 02:01 PM

Thanks for the input! I am really starting to think that may be a real possibility. I know my grandfather wouldn't have done that when he owned it. But, seeing as my great uncle, the original owner, added saddle tanks and a trans cooler, so he could pull his horse trailers on his ranch, it really make sense. I'll have to grill my grandfather to see what he knows. I really presumed everything was factory (virtually everything else is), because of their traditional "if it aint broke, don't fix it" mentality.

1972SUPERSB · 12-20-2012, 02:10 PM

Quote:

Originally Posted by IHeartGroceries

Thanks for the input! I am really starting to think that may be a real possibility. I know my grandfather wouldn't have done that when he owned it. But, seeing as my great uncle, the original owner, added saddle tanks and a trans cooler, so he could pull his horse trailers on his ranch, it really make sense. I'll have to grill my grandfather to see what he knows. I really presumed everything was factory (virtually everything else is), because of their traditional "if it aint broke, don't fix it" mentality.

There is a gear ratio calculator which you can google and will tell you what your ratio is. Just need height of tires. Need a tach to get accurate results.Or you can just jack up the rear end of the truck and note how many times the driveshaft turns in relation to the tire
Posted via Mobile Device

12-19-2012, 09:50 PM	#1
bkkpool Registered User Join Date: Jul 2012 Location: Gurley, AL Posts: 36	What rear end? Can anyone tell me what rear end is in this truck from the SPID? Posted via Mobile Device Posted via Mobile Device

12-19-2012, 09:52 PM	#2
Tinkermc Registered User Join Date: Jul 2011 Location: Farmville, Va Posts: 3,026	Re: What rear end? I may be wrong but to my knowledge no

12-20-2012, 12:24 AM	#4
dan42 Registered User Join Date: Feb 2007 Location: Cali Central Coast Posts: 5,191	Re: What rear end? It's a half ton, and I believe the standard rear end was probably a 3 .73 12 bolt. Posted via Mobile Device __________________ '67 SWB Fleetside ZZ4/350/Tremec 5-speed/4link/Scott's IFS - and fun as heck! SOLD Click here to support the board Philippians 4: 6-7

12-20-2012, 12:58 AM	#5
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,105	Re: What rear end? Unless it shows something specific on the spid, i'm pretty sure big blocks with automatics came with a 3:08 Ratio. Posted via Mobile Device __________________ 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

12-20-2012, 01:00 AM	#6
bkkpool Registered User Join Date: Jul 2012 Location: Gurley, AL Posts: 36	Re: What rear end? Will it be an open or limited slip in a BB truck? Posted via Mobile Device

12-20-2012, 01:22 AM	#8
Already Gone 70+ ( Old Skool Club ) Join Date: Nov 2003 Location: Saskatoon, Saskatchewan ,Canada Posts: 9,105	Re: What rear end? I am 99% sure if the truck came with Limited-Slip Positraction it was an option so it'd be on the spid. Are you sure the original rearvend is in your truck? Posted via Mobile Device __________________ 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

12-20-2012, 01:41 AM	#9
bkkpool Registered User Join Date: Jul 2012 Location: Gurley, AL Posts: 36	Re: What rear end? I'm fairly confident it is the original rear end. I'm considering buying it for parts and to part out. Unfortunately the motor was swapped 20+ years ago. I may go see the truck this weekend. Posted via Mobile Device

12-20-2012, 04:23 AM	#10
SS Tim Registered User Join Date: Aug 2010 Location: Edwards, CA Posts: 7,503	Re: What rear end? Chevy 3500lb axle (AKA 12 bolt). 3.07 gears with no listed option except open or posi.. Attached Images __________________ Thanks, Tim * VIN/Model Decoders * Power Team Charts (engine/transmission/gear ratio) * Post Your Pickup SPID Blazer SPID Suburban/Panel SPID * RTFM ... Read The Factory Manuals... download 'em here Highlanders Do you have a 1972 Plaid Pickup? Plaid Blazer ** Plaid Suburban

12-20-2012, 11:00 AM	#11
bkkpool Registered User Join Date: Jul 2012 Location: Gurley, AL Posts: 36	Re: What rear end? It appears that it is an open 3.07.Thanks for the info.

12-20-2012, 11:30 AM	#12
IHeartGroceries Registered User Join Date: Dec 2010 Location: TX Posts: 65	Re: What rear end? The SPID on my truck (350/350) doesn't list any particulars about the rear end. So, from what you guys are saying, it is safe to assume it uses standard eqipment (3.07). However, there is no way the rear end has 3.07 in it. It is wound like a top at 60MPH. It is nearly unbearable. I don't have a tach, but I'd estimate 3500 RPM @ 60 MPH. Any ideas? At what RPM should 3.07 be @ 60 MPH? I might as well just yank the cover and look in the case. It has started dropping oil anyway.

12-20-2012, 02:01 PM	#14
IHeartGroceries Registered User Join Date: Dec 2010 Location: TX Posts: 65	Re: What rear end? Thanks for the input! I am really starting to think that may be a real possibility. I know my grandfather wouldn't have done that when he owned it. But, seeing as my great uncle, the original owner, added saddle tanks and a trans cooler, so he could pull his horse trailers on his ranch, it really make sense. I'll have to grill my grandfather to see what he knows. I really presumed everything was factory (virtually everything else is), because of their traditional "if it aint broke, don't fix it" mentality.



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.