1987 Diff same as 1988?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

kelsfine69 · 07-18-2011, 08:03 PM

Pretty sure I Know the answew but I thought Id check anyway. 1987 was the last of the squares as everyone knows. Is the diff the same or close as a 1988. I can get an 1988 rear diff for 100 bucks so the price is right but not if it dont work. I need a 3:42 Posi cause mine is Hoop'd.

SSC's76 · 07-18-2011, 08:35 PM

88 is slightly longer about an inch on either side.depending on your wheel backspacing may not effect clearances usually doesent. the only thing I dont recall off hand is if you would need a different u joint. for the price might be a good option unless the new diff is a grenade lock.

Pop's C-10 · 07-18-2011, 11:55 PM

You may be able to swp tha whole axle, but tha posi unit won't swap...if that's what you mean...28 spline vs 30 spline..

USSkoval · 07-18-2011, 11:58 PM

Is it from a new body style truck, or an '88 Burb? The new body style axle would need the spring perches and shock mounts cut off and welded back on in the correct spot.

67_SS396 · 07-19-2011, 11:55 PM

Quote:

Originally Posted by Pop's C-10

You may be able to swp tha whole axle, but tha posi unit won't swap...if that's what you mean...28 spline vs 30 spline..

The 87 should have a 30 spline carrier if it's original to the truck.
Posted via Mobile Device

kelsfine69 · 07-22-2011, 12:34 PM

Yes all original..Are 3:42 non posi common to find?

kelsfine69 · 08-11-2011, 10:46 AM

does anyone know?

motornut · 07-19-2011, 07:06 AM

Quote:

Originally Posted by kelsfine69

Pretty sure I Know the answew but I thought Id check anyway. 1987 was the last of the squares as everyone knows. Is the diff the same or close as a 1988. I can get an 1988 rear diff for 100 bucks so the price is right but not if it dont work. I need a 3:42 Posi cause mine is Hoop'd.

i have an 88 square burb ,and it's the same as my 87 burb .....not like my 89 burb the front changed

kelsfine69 · 07-19-2011, 10:42 AM

Yea thought so..My 3:42 gov has seen better days and I would like to swap in a whole diff rather than tear it apart. If i cant find another what would be the way to go to get a 3:42 posi in a 10 bolt without going back to the Gov-bomb? Mayby I should look for a 3:42 Non Posi?

motornut · 08-12-2011, 07:10 AM

Quote:

Originally Posted by motornut

i have an 88 square burb ,and it's the same as my 87 burb .....not like my 89 burb the front changed

88 is 3.73
duno bout the 87

67_SS396 · 08-11-2011, 11:46 PM

3.42 is quite common in the 88-up.
Posted via Mobile Device

07-18-2011, 08:03 PM	#1
kelsfine69 18 Till I Die Join Date: Mar 2005 Location: Alberta, Canada Posts: 1,522	1987 Diff same as 1988?? Pretty sure I Know the answew but I thought Id check anyway. 1987 was the last of the squares as everyone knows. Is the diff the same or close as a 1988. I can get an 1988 rear diff for 100 bucks so the price is right but not if it dont work. I need a 3:42 Posi cause mine is Hoop'd. __________________ 2011 GMC Acadia 1969 GMC BBC LS7 2007 GMC Crew Duramax 1987 Camaro Iroc 350 Tuned Port Injection 42000Km 1987 Chevrolet Silverado 350 TBI 1987 Chevrolet Silverado 350 TBI(yes 2) Take me drunk, I'm too home...

07-18-2011, 08:35 PM	#2
SSC's76 No No Join Date: Jun 2005 Location: Pueblo Colorado Posts: 1,781	Re: 1987 Diff same as 1988?? 88 is slightly longer about an inch on either side.depending on your wheel backspacing may not effect clearances usually doesent. the only thing I dont recall off hand is if you would need a different u joint. for the price might be a good option unless the new diff is a grenade lock. __________________ 1976 Custom Deluxe SWB Med FMB.3/4 Drop. Gen VI 454, Muncie HD 3 speed With Modified OE Hurst Shifter, 3.73 12 bolt, GMPP HO roller cam, Hooker headers, Performer intake with modified Q-jet, Accel distributor. Best 1/4 12.3 @108. Funnest run 19.84 @88 full 1/4 mile burn out. 1997 K1500 ext cab 5.7 stock except muffler

07-18-2011, 11:55 PM	#3
Pop's C-10 Registered User Join Date: Jul 2010 Location: memphis Posts: 2,537	Re: 1987 Diff same as 1988?? You may be able to swp tha whole axle, but tha posi unit won't swap...if that's what you mean...28 spline vs 30 spline.. __________________ 1981 C-10 (Pop's) 1978 Camaro 2006 Lacrosse

07-18-2011, 11:58 PM	#4
USSkoval Registered User Join Date: Jul 2009 Location: West Jefferson, OH Posts: 999	Re: 1987 Diff same as 1988?? Is it from a new body style truck, or an '88 Burb? The new body style axle would need the spring perches and shock mounts cut off and welded back on in the correct spot. __________________ -Andy '77 K5 Blazer '78 K10 Shortbed '78 C20 Suburban '79 K30 Crew Cab Dually '84 C10 Short Stepside '88 K20 Suburban

07-22-2011, 12:34 PM	#6
kelsfine69 18 Till I Die Join Date: Mar 2005 Location: Alberta, Canada Posts: 1,522	Re: 1987 Diff same as 1988?? Yes all original..Are 3:42 non posi common to find? __________________ 2011 GMC Acadia 1969 GMC BBC LS7 2007 GMC Crew Duramax 1987 Camaro Iroc 350 Tuned Port Injection 42000Km 1987 Chevrolet Silverado 350 TBI 1987 Chevrolet Silverado 350 TBI(yes 2) Take me drunk, I'm too home...

08-11-2011, 10:46 AM	#7
kelsfine69 18 Till I Die Join Date: Mar 2005 Location: Alberta, Canada Posts: 1,522	Re: 1987 Diff same as 1988?? does anyone know? __________________ 2011 GMC Acadia 1969 GMC BBC LS7 2007 GMC Crew Duramax 1987 Camaro Iroc 350 Tuned Port Injection 42000Km 1987 Chevrolet Silverado 350 TBI 1987 Chevrolet Silverado 350 TBI(yes 2) Take me drunk, I'm too home...

07-19-2011, 10:42 AM	#9
kelsfine69 18 Till I Die Join Date: Mar 2005 Location: Alberta, Canada Posts: 1,522	Re: 1987 Diff same as 1988?? Yea thought so..My 3:42 gov has seen better days and I would like to swap in a whole diff rather than tear it apart. If i cant find another what would be the way to go to get a 3:42 posi in a 10 bolt without going back to the Gov-bomb? Mayby I should look for a 3:42 Non Posi? __________________ 2011 GMC Acadia 1969 GMC BBC LS7 2007 GMC Crew Duramax 1987 Camaro Iroc 350 Tuned Port Injection 42000Km 1987 Chevrolet Silverado 350 TBI 1987 Chevrolet Silverado 350 TBI(yes 2) Take me drunk, I'm too home...

08-11-2011, 11:46 PM	#11
67_SS396 Registered User Join Date: Mar 2000 Location: Blue Ridge, Tx Posts: 1,172	Re: 1987 Diff same as 1988?? 3.42 is quite common in the 88-up. Posted via Mobile Device __________________ Fawker Fab three seater rock crawler buggy 498 BBC/SM465/203/205 doubler, propane, 5.13's, 42" PB Rockers '66 C10 - The new hot rod '77 3+3 Dually - 12 valve 4wd conversion tow rig project '28 Ford 2 door sedan street rod RevLimit Offroad "Hang on beer, we can do this."



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