4.11 and posi trak - The 1947 - Present Chevrolet & GMC Truck Message Board Network

*71SWB* · 10-10-2013, 01:23 PM

I see in the for sale section there are a 12 bolt 4.11 gears and posi trak out of a 67 suburban for sale. Will these fit a 71 c10 swb 2 wd ?

**uncle** · 10-10-2013, 01:26 PM

Yes

*71SWB* · 10-10-2013, 01:56 PM

Does changing to the 4.11 effect the RPM'S alot when driving?

**WIDESIDE72** · 10-10-2013, 01:58 PM

What gears do you have now?

*71SWB* · 10-10-2013, 02:26 PM

I was told 3.08 (stock)

**steelhorse** · 10-10-2013, 02:57 PM

OH yes will be quite a bit higher at highway speeds.

88Ironduke · 10-10-2013, 05:59 PM

I have the posi rear end in my 72', not sure of ratio but I assume it a 4-11 because the old 250 howls at 55mph. When I was kid my father had a 69' 4wd with a 292/4spd (very cool with the military bed on it) and the posi rear diff allowed the two wheel drive truck access in the woods with the 4wd out front. It could go everywhere but it spent a lot of time in the woods hauling wood. Its a really good fit.

88Ironduke

BADPURPLE70CHEVY · 10-10-2013, 06:03 PM

Quote:

Originally Posted by dossfatboy

Does changing to the 4.11 effect the RPM'S alot when driving?

I have a 4:11 gear in mine and yes on the highway it screams but red light to red light it will flat get it.

GMCJOE · 10-10-2013, 08:01 PM

Quote:

Originally Posted by BADPURPLE70CHEVY

I have a 4:11 gear in mine and yes on the highway it screams but red light to red light it will flat get it.

Ain't no lie about that!

*71SWB* · 10-10-2013, 08:02 PM

thank you all for the info. as ive mentioned before i am a non mechanic and was concerned it would require something additional to install vs a removal and place in the 4.11 n posi carrier. I currently don't have posi. I also was told a 67 suburban had leaf springs and I have coils so I was afraid that would be an issue.

10-10-2013, 01:23 PM	#1
71SWB Registered User Join Date: Aug 2013 Location: Va Posts: 165	4.11 and posi trak I see in the for sale section there are a 12 bolt 4.11 gears and posi trak out of a 67 suburban for sale. Will these fit a 71 c10 swb 2 wd ?

10-10-2013, 01:26 PM	#2
uncle Senior Member Join Date: Aug 2003 Location: Conyers,Ga. Posts: 7,286	Re: 4.11 and posi trak Yes

10-10-2013, 01:56 PM	#3
71SWB Registered User Join Date: Aug 2013 Location: Va Posts: 165	Re: 4.11 and posi trak Does changing to the 4.11 effect the RPM'S alot when driving?

10-10-2013, 01:58 PM	#4
WIDESIDE72 Senior Member Join Date: Aug 2008 Location: Cedar Park, Texas Posts: 7,494	Re: 4.11 and posi trak What gears do you have now?

10-10-2013, 02:26 PM	#5
71SWB Registered User Join Date: Aug 2013 Location: Va Posts: 165	Re: 4.11 and posi trak I was told 3.08 (stock)

10-10-2013, 02:57 PM	#6
steelhorse Senior Member Join Date: Apr 2008 Location: Franklinton NC Posts: 1,309	Re: 4.11 and posi trak OH yes will be quite a bit higher at highway speeds.

10-10-2013, 05:59 PM	#7
88Ironduke Registered User Join Date: Jul 2010 Location: Willingboro, NJ Posts: 489	Re: 4.11 and posi trak I have the posi rear end in my 72', not sure of ratio but I assume it a 4-11 because the old 250 howls at 55mph. When I was kid my father had a 69' 4wd with a 292/4spd (very cool with the military bed on it) and the posi rear diff allowed the two wheel drive truck access in the woods with the 4wd out front. It could go everywhere but it spent a lot of time in the woods hauling wood. Its a really good fit. 88Ironduke __________________ Retired USAF - No rockets, no mortars, no bad guys shooting...No stress!!! My Build Thread: Project 72' Green http://67-72chevytrucks.com/vboard/s...d.php?t=587932

10-10-2013, 08:02 PM	#10
71SWB Registered User Join Date: Aug 2013 Location: Va Posts: 165	Re: 4.11 and posi trak thank you all for the info. as ive mentioned before i am a non mechanic and was concerned it would require something additional to install vs a removal and place in the 4.11 n posi carrier. I currently don't have posi. I also was told a 67 suburban had leaf springs and I have coils so I was afraid that would be an issue.



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