??? on gearing in 68 duallie rear - The 1947 - Present Chevrolet & GMC Truck Message Board Network

StepinNJ · 01-11-2013, 05:41 PM

What would the gearing be in a 68 chevy duallie rear end that would have been in a tow truck back then? Were there a lot of options or just a few?

**kwmech** · 01-11-2013, 05:57 PM

4.10 or 4.56 most common

**special-K** · 01-11-2013, 08:27 PM

Most likely 5.13s

StepinNJ · 01-12-2013, 12:35 AM

Are they replaceable?? More highway driving gears?

SS Tim · 01-12-2013, 01:19 AM

Tim has it right 5.14 with the HO72 & RO5 DRW option (9000 or 10000GVW). But if by some chance it has the 11K rear axle they would be 6.17s (14000 GVW). If you do have the HO72 then the 4.10s from a SRW pickup should drop right in and that is 20% right there unless you are running tiny tires too.

BarryB · 01-12-2013, 01:22 AM

6:17's???? Good lord I bet the motors were screaming at 45 mph. But I also bet it sure would pull.

**special-K** · 01-12-2013, 08:31 AM

Quote:

Originally Posted by StepinNJ

Are they replaceable?? More highway driving gears?

These rears are extremely easy to change ratio on. It's bolt-in. You pull the axle shafts back,disconnect the driveshaft,remove the entire differential assembly as a unit from the front,and reverse all steps. 4.10 is the tallest gearing you will get. My '92 K3500 has 4.10s with 5spd overdrive and it's perfect. Got grunt power,compression braking,and an excellent hiway machine. Actually,my '85 Jimmy is also 4.10 w/overdrive and an excellent hiway machine as well as great off road and towing. My '72 K2500 has 4.10s with no overdrive and it cruises just fine at 65. I used to drive them 75-80 all day long just fine. These days I am saving fuel at 60-65

StepinNJ · 01-12-2013, 11:03 AM

The problem is this rear is in a 70 K20 pick up I'm looking at. Was installed 30 years ago so I don't know what wrecker type it came out of. Is the axle marked somewhere?

SS Tim · 01-12-2013, 04:39 PM

Here is an ID chart for '68.

bobs409 · 01-13-2013, 07:43 AM

My 69 wrecker has a factory 4.10. (thank God!) I'll let the 6.17's for you guys.

Heck, I put a 4.57 in my daily driver once and could actually watch the fuel gauge decline as I drove it! NO THANK YOU!!!

bobs409 · 01-13-2013, 07:46 AM

Now that I think about this, 6.17!

Geez, top speed in 1st with a 4.10 is about 5mph. What would a 6.17 do to that!

**special-K** · 01-13-2013, 10:24 AM

My wrecker has 5.13s and it can comfortably pull 4th gear at 20-25. I can start in 3rd and it feels about how a three on the tree starts out. Starting in 2nd,I'm in 4th in about 60'. I have a 4.10/No-Spin for it,if I end up keeping it

StepinNJ · 01-13-2013, 01:18 PM

This is a 350 4 bbl with a 3 speed auto trans. I will check for numbers.

**rs74** · 01-13-2013, 06:29 PM

I know we are talking about a 68 but my father-n-law says his 67 GMC with a 305 and 4-speed came out with what he calls highway gears new. He said that it is so high that he couldn't use it in the field farming. Although he did haul rock on it for a living for a while. So not sure what to think about it. Maybe he has the 4.10's

**special-K** · 01-13-2013, 06:53 PM

4.10 would be the hiway gears. I had a '70 CST/30 Custom Camper 157" cab & chassis that started life as a Winnebago RV. It had a TH400 and obviously was mean to travel the hiways. It had 4.10s. There were aftermarket ring & pinions available for a 3.90 ratio...big whoop! Not much change there.

01-11-2013, 05:41 PM	#1
StepinNJ TuTone Silverado Join Date: Mar 2007 Location: Central NJ Posts: 196	??? on gearing in 68 duallie rear What would the gearing be in a 68 chevy duallie rear end that would have been in a tow truck back then? Were there a lot of options or just a few? __________________ 13 Corvette GS vert 13 Ram Laramie Longhorn 11 Wrangler Sahara unlimited 08 300 76 El Camino 67 Bel Air sedan 63 Corvette SWC 08 HD Road King Classic 68 HD Golf car

01-11-2013, 05:57 PM	#2
kwmech Senior Member Join Date: Mar 2003 Location: Colfax-California Posts: 8,487	Re: ??? on gearing in 68 duallie rear 4.10 or 4.56 most common

01-11-2013, 08:27 PM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: ??? on gearing in 68 duallie rear Most likely 5.13s __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~

01-12-2013, 12:35 AM	#4
StepinNJ TuTone Silverado Join Date: Mar 2007 Location: Central NJ Posts: 196	Re: ??? on gearing in 68 duallie rear Are they replaceable?? More highway driving gears? __________________ 13 Corvette GS vert 13 Ram Laramie Longhorn 11 Wrangler Sahara unlimited 08 300 76 El Camino 67 Bel Air sedan 63 Corvette SWC 08 HD Road King Classic 68 HD Golf car

01-12-2013, 01:19 AM	#5
SS Tim Registered User Join Date: Aug 2010 Location: Edwards, CA Posts: 7,503	Re: ??? on gearing in 68 duallie rear Tim has it right 5.14 with the HO72 & RO5 DRW option (9000 or 10000GVW). But if by some chance it has the 11K rear axle they would be 6.17s (14000 GVW). If you do have the HO72 then the 4.10s from a SRW pickup should drop right in and that is 20% right there unless you are running tiny tires too. 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

01-12-2013, 01:22 AM	#6
BarryB Senior Member Join Date: Jul 2006 Location: Blountville, Tn. Posts: 3,904	Re: ??? on gearing in 68 duallie rear 6:17's???? Good lord I bet the motors were screaming at 45 mph. But I also bet it sure would pull. __________________ We could learn a lot from crayons... Some are sharp; some are pretty;and some are dull. Some have weird names; and all are different colours;but they all have to live in the same box. You may be only one person in the world, But you may also be the world to one person. * Some mistakes are too much fun to only make once. Two rules in life. 1. Never sweat the small stuff! 2. Everything is small stuff!

01-12-2013, 11:03 AM	#8
StepinNJ TuTone Silverado Join Date: Mar 2007 Location: Central NJ Posts: 196	Re: ??? on gearing in 68 duallie rear The problem is this rear is in a 70 K20 pick up I'm looking at. Was installed 30 years ago so I don't know what wrecker type it came out of. Is the axle marked somewhere? __________________ 13 Corvette GS vert 13 Ram Laramie Longhorn 11 Wrangler Sahara unlimited 08 300 76 El Camino 67 Bel Air sedan 63 Corvette SWC 08 HD Road King Classic 68 HD Golf car

01-12-2013, 04:39 PM	#9
SS Tim Registered User Join Date: Aug 2010 Location: Edwards, CA Posts: 7,503	Re: ??? on gearing in 68 duallie rear Here is an ID chart for '68. 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

01-13-2013, 07:43 AM	#10
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	Re: ??? on gearing in 68 duallie rear My 69 wrecker has a factory 4.10. (thank God!) I'll let the 6.17's for you guys. Heck, I put a 4.57 in my daily driver once and could actually watch the fuel gauge decline as I drove it! NO THANK YOU!!! __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

01-13-2013, 07:46 AM	#11
bobs409 1969 Custom 30 wrecker Join Date: Sep 2001 Location: Pottsville, Pa Posts: 2,611	Re: ??? on gearing in 68 duallie rear Now that I think about this, 6.17! Geez, top speed in 1st with a 4.10 is about 5mph. What would a 6.17 do to that! __________________ Bob 63 Impala 283/PG/3.36 (under restoration) 66 Impala 327/PG/3.36 66 Chevelle SS 409/M22/3.55 69 Chevelle 307/PG/3.08 (future restoration) 69 C10 short stepside 454/TH350/3.73 69 Custom 30 tow truck 350/4 spd/4.10 (resto done, CRUISIN TIME!) 71 Cheyenne 20 fleetside 350/4 spd/4.10 71 Chevelle 6/PG/3.08 72 Chevelle 454/M21/4.10

01-13-2013, 10:24 AM	#12
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: ??? on gearing in 68 duallie rear My wrecker has 5.13s and it can comfortably pull 4th gear at 20-25. I can start in 3rd and it feels about how a three on the tree starts out. Starting in 2nd,I'm in 4th in about 60'. I have a 4.10/No-Spin for it,if I end up keeping it __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~ Last edited by special-K; 01-13-2013 at 06:48 PM.

01-13-2013, 01:18 PM	#13
StepinNJ TuTone Silverado Join Date: Mar 2007 Location: Central NJ Posts: 196	Re: ??? on gearing in 68 duallie rear This is a 350 4 bbl with a 3 speed auto trans. I will check for numbers. __________________ 13 Corvette GS vert 13 Ram Laramie Longhorn 11 Wrangler Sahara unlimited 08 300 76 El Camino 67 Bel Air sedan 63 Corvette SWC 08 HD Road King Classic 68 HD Golf car

01-13-2013, 06:29 PM	#14
rs74 Senior Member Join Date: Jun 2010 Location: Illinois Posts: 2,957	Re: ??? on gearing in 68 duallie rear I know we are talking about a 68 but my father-n-law says his 67 GMC with a 305 and 4-speed came out with what he calls highway gears new. He said that it is so high that he couldn't use it in the field farming. Although he did haul rock on it for a living for a while. So not sure what to think about it. Maybe he has the 4.10's

01-13-2013, 06:53 PM	#15
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: ??? on gearing in 68 duallie rear 4.10 would be the hiway gears. I had a '70 CST/30 Custom Camper 157" cab & chassis that started life as a Winnebago RV. It had a TH400 and obviously was mean to travel the hiways. It had 4.10s. There were aftermarket ring & pinions available for a 3.90 ratio...big whoop! Not much change there. __________________ "BUILDING A BETTER WAY TO SERVE THE USA"......67/72......"The New Breed" GMC '67 C1500 Wideside Super Custom SWB: 327/M22/3.42 posi.........."The '67" (project) GMC '72 K2500 Wideside Sierra Custom Camper: 350/TH350/4.10 Power-Lok..."The '72" (rolling) Tim "Don't call me a redneck. I'm a rough cut country gentleman" R.I.P. ~ East Side Low Life ~ El Jay ~ 72BLUZ ~ Fasteddie69 ~ Ron586 ~ 67ChevyRedneck ~ Grumpy Old Man ~



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