86 c10 rearend ? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

lifted k10 · 11-02-2011, 04:56 PM

Hey guys I have a 86 c10 gmc step side 4.3 4 speed with granny first gear. My qestion is what gears do I have in the rearend and will my current bell housing fit a 350 engine?
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Tx Firefighter · 11-02-2011, 05:14 PM

No way of knowing the gear ratio short of checking it personally. You'll have to either jack it up and spin the wheels or remove the cover and see the gear tooth count.

Bellhousing fits a small block fine with no mods.

lifted k10 · 11-02-2011, 05:37 PM

What about the flywheel will it fit on a 350 too?
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406 Q-ship · 11-02-2011, 06:48 PM

The bellhousing from the 4.3 will bolt to any SBC, the flywheel should be from the later one piece rear main seal design. I am not sure if the balance on the 4.3 in 1986 and later is the same as the 350 after 1986. The flywheel will not fit any 1985 or earlier two piece rear main seal SBC, bolt pattern is different.

PS 400 SBC will not interchange with the 4.3 flywheel under any case.

Slonaker · 11-09-2011, 01:25 PM

Quote:

Originally Posted by lifted k10

Hey guys I have a 86 c10 gmc step side 4.3 4 speed with granny first gear. My qestion is what gears do I have in the rearend and will my current bell housing fit a 350 engine?
Posted via Mobile Device

My '86 Chevy lists the gears on the tag in the glovebox. Maybe yours does as well?

Slonaker

Keith Seymore · 11-10-2011, 08:20 AM

Quote:

Originally Posted by Slonaker

My '86 Chevy lists the gears on the tag in the glovebox. Maybe yours does as well?

Slonaker

In my experience the SPID lists optional gears, along with the RPO, but not the base (std) gear ratio.

Quote:

Originally Posted by lifted k10

Hey guys I have a 86 c10 gmc step side 4.3 4 speed with granny first gear. My qestion is what gears do I have in the rearend

According to the powertrain charts listed in the GM Heritage Center info packet (http://www.gmheritagecenter.com/gm-h...olet-Truck.pdf - page 19) it depends on the GVW. There is a base axle as 3.08 (4900/5200 lbs gvw), 3.42 (5600 gvw) or 3.73 (6100 gvw). That's assuming that they've never been changed.

Like TXFirefighter says: no way of knowing without checkin' em out.

K

ElGracho · 11-10-2011, 09:29 AM

My 85 with the 4.3 and 4 speed has 2.73 gears.... Not for long though...

Keith Seymore · 11-10-2011, 01:45 PM

Quote:

Originally Posted by ElGracho

My 85 with the 4.3 and 4 speed has 2.73 gears.... Not for long though...

My bad - you are correct. There is an entry for a 2.73 base gearset (page 20). I was accidentally looking at the wrong chart (for California emissions).

K

Keith Seymore · 11-10-2011, 02:44 PM

Here's a copy of the actual powertrain chart, so that we are all on the same page:

11-02-2011, 04:56 PM	#1
lifted k10 Registered User Join Date: Apr 2009 Location: new britain , ct. Posts: 19	86 c10 rearend ? Hey guys I have a 86 c10 gmc step side 4.3 4 speed with granny first gear. My qestion is what gears do I have in the rearend and will my current bell housing fit a 350 engine? Posted via Mobile Device

11-02-2011, 05:14 PM	#2
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Re: 86 c10 rearend ? No way of knowing the gear ratio short of checking it personally. You'll have to either jack it up and spin the wheels or remove the cover and see the gear tooth count. Bellhousing fits a small block fine with no mods. __________________ I'm on the Instagram- @Gearhead_Kevin

11-02-2011, 05:37 PM	#3
lifted k10 Registered User Join Date: Apr 2009 Location: new britain , ct. Posts: 19	Re: 86 c10 rearend ? What about the flywheel will it fit on a 350 too? Posted via Mobile Device

11-02-2011, 06:48 PM	#4
406 Q-ship Registered User Join Date: Oct 2010 Location: Largo Florida Posts: 632	Re: 86 c10 rearend ? The bellhousing from the 4.3 will bolt to any SBC, the flywheel should be from the later one piece rear main seal design. I am not sure if the balance on the 4.3 in 1986 and later is the same as the 350 after 1986. The flywheel will not fit any 1985 or earlier two piece rear main seal SBC, bolt pattern is different. PS 400 SBC will not interchange with the 4.3 flywheel under any case. __________________ Lifes journey is not to arrive at the gate well preserved, it is to slide in sideways all used up and wore out yelling.....God what'a ride! Where patience fails, force prevails Stapp's Ironical Paradox "The universal aptitude for ineptitude makes any human accomplishment an incredible miracle."

11-10-2011, 09:29 AM	#7
ElGracho Gentleman Jim Driver Join Date: Nov 2002 Location: Poulsbo, WA Posts: 1,553	Re: 86 c10 rearend ? My 85 with the 4.3 and 4 speed has 2.73 gears.... Not for long though... __________________ Joe '75 GMC Gentleman Jim '84 Chev C10 Short Wide - Super duper plain (manual steering, manual brakes, no dome light, no cig lighter) '85 Chev C10 Short Wide - Super plain Vortec 4.8 4L60E trans also: '81 K30, '83 C30 Crew Dually, '84 M1028 CUCV, '85 M1009 CUCV, another '85 C10 SWB, '89 R3500 Flatbed

11-10-2011, 02:44 PM	#9
Keith Seymore Registered User Join Date: May 2009 Location: Motor City Posts: 9,226	Re: 86 c10 rearend ? Here's a copy of the actual powertrain chart, so that we are all on the same page: __________________ Chevrolet Flint Assembly 1979-1986 GM Full Size Truck Engineering 1986 - 2019 Intro from an Old Assembly Guy: http://67-72chevytrucks.com/vboard/s...d.php?t=342926 My Pontiac story: http://forums.maxperformanceinc.com/...d.php?t=560524 Chevelle intro: http://www.superchevy.com/features/s...hevy-chevelle/



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