1969 C20 rear axle; what were the options?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

VTKidder · 08-15-2007, 09:05 AM

I'm looking at a '69 longbox pickup, 3/4 ton, 2WD, 307 with 4-speed floor shift transmission, 16" wheels, power drum brakes all the way around. The rear suspension is trailing arms with coil springs. I was unable to look in the glovebox for the RPO codes to indicate what rear end the truck has, but the rear end is very large, and has a drain plug right in the back of it. What were the options for rear ends, and ratios on a '69 3/4 ton with the 307??? Thanks!

-adam

Longhorn Man · 08-15-2007, 03:52 PM

that would be the eaton/corperate rear... 4.57 gear unless optioned with the 4.10 or 5.13.

BCOWANWHEELS · 08-15-2007, 08:35 PM

i,ve got a 4.10 chunk and a disc brake front end setup for that truck i,d sell reasonable.
bob in tn.

**special-K** · 08-15-2007, 10:28 PM

If it`s an Eaton,than the ratios given are what it could be.But,if the differential cover isn`t round,than it`s a Dana and it could be opted with a 3.73,but not standard with a 307.

Longhorn Man · 08-15-2007, 11:17 PM

Tim... it's a 3/4 ton... the best you could do in a 3/4 ton was a 3.54, and I am 99% positive that was only with the big block. The only other gear I've seen in a 3/4 ton dana is the 4.10.

VTKidder · 08-16-2007, 07:00 AM

I looked at the rear, and it was round with a center drain plug...after further investigation, it looks to be the Eaton H052. As far as ratio, I have no idea. I'll have to check the glovebox and see. No word on the sale though...owner is playing coy with me.

**special-K** · 08-16-2007, 08:18 AM

My`72 K2500 has what I thought was 3.73s,although I never pulled the cover to varify.They must be 3.54s,then,because they are definately more hiway friendly than the 4.10 trucks.The guy I bought it from said he thought they were 3.73s from his hiway experience with it.At one point I had taken the wheels & tires that were on my`72 CheyenneSuper w/4.10s and put them on the GMC.They are both the same engine/trans with tachs and I`m sure the GMC had higher gears.It even ended up with the same motor in it.
So,either they were swapped,if available,or it was spec`d with 3.54s.Anyway,VTKidder,since you don`t have a Dana this is just for general knowledge.Try spinning your rear wheels and count the turns on the driveshaft.If the wheel turns right about 4 times(just past)for one d-shaft spin you have 4.10s.If the wheel goes about 4 1/2 then you have 4.56s.I`ve never had a ratio listed on a glovebox,standard or optional.

VTKidder · 08-16-2007, 10:59 AM

I was hoping the glovebox would show something; my '86 K20 says it has 4.10's on the RPO sticker. Do you know what the 4-speed floor-shift tranny is? Is it an SM420??

cruiserman · 08-16-2007, 02:19 PM

1969 would be a SM465.

08-15-2007, 09:05 AM	#1
VTKidder Registered User Join Date: May 2003 Location: Vermont Posts: 996	1969 C20 rear axle; what were the options?? I'm looking at a '69 longbox pickup, 3/4 ton, 2WD, 307 with 4-speed floor shift transmission, 16" wheels, power drum brakes all the way around. The rear suspension is trailing arms with coil springs. I was unable to look in the glovebox for the RPO codes to indicate what rear end the truck has, but the rear end is very large, and has a drain plug right in the back of it. What were the options for rear ends, and ratios on a '69 3/4 ton with the 307??? Thanks! -adam

08-15-2007, 03:52 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 1969 C20 rear axle; what were the options?? that would be the eaton/corperate rear... 4.57 gear unless optioned with the 4.10 or 5.13.

08-15-2007, 08:35 PM	#3
BCOWANWHEELS Registered User Join Date: Nov 2006 Location: KINGSPORT,TN. Posts: 3,035	Re: 1969 C20 rear axle; what were the options?? i,ve got a 4.10 chunk and a disc brake front end setup for that truck i,d sell reasonable. bob in tn. __________________ I BELIEVE IN JOHN 3:16

08-15-2007, 10:28 PM	#4
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: 1969 C20 rear axle; what were the options?? If it`s an Eaton,than the ratios given are what it could be.But,if the differential cover isn`t round,than it`s a Dana and it could be opted with a 3.73,but not standard with a 307. __________________ "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 ~

08-15-2007, 11:17 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: 1969 C20 rear axle; what were the options?? Tim... it's a 3/4 ton... the best you could do in a 3/4 ton was a 3.54, and I am 99% positive that was only with the big block. The only other gear I've seen in a 3/4 ton dana is the 4.10.

08-16-2007, 07:00 AM	#6
VTKidder Registered User Join Date: May 2003 Location: Vermont Posts: 996	Re: 1969 C20 rear axle; what were the options?? I looked at the rear, and it was round with a center drain plug...after further investigation, it looks to be the Eaton H052. As far as ratio, I have no idea. I'll have to check the glovebox and see. No word on the sale though...owner is playing coy with me.

08-16-2007, 08:18 AM	#7
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,863	Re: 1969 C20 rear axle; what were the options?? My`72 K2500 has what I thought was 3.73s,although I never pulled the cover to varify.They must be 3.54s,then,because they are definately more hiway friendly than the 4.10 trucks.The guy I bought it from said he thought they were 3.73s from his hiway experience with it.At one point I had taken the wheels & tires that were on my`72 CheyenneSuper w/4.10s and put them on the GMC.They are both the same engine/trans with tachs and I`m sure the GMC had higher gears.It even ended up with the same motor in it. So,either they were swapped,if available,or it was spec`d with 3.54s.Anyway,VTKidder,since you don`t have a Dana this is just for general knowledge.Try spinning your rear wheels and count the turns on the driveshaft.If the wheel turns right about 4 times(just past)for one d-shaft spin you have 4.10s.If the wheel goes about 4 1/2 then you have 4.56s.I`ve never had a ratio listed on a glovebox,standard or optional. __________________ "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 ~

08-16-2007, 10:59 AM	#8
VTKidder Registered User Join Date: May 2003 Location: Vermont Posts: 996	Re: 1969 C20 rear axle; what were the options?? I was hoping the glovebox would show something; my '86 K20 says it has 4.10's on the RPO sticker. Do you know what the 4-speed floor-shift tranny is? Is it an SM420??

08-16-2007, 02:19 PM	#9
cruiserman Registered User Join Date: Dec 2006 Location: Idaho Posts: 210	Re: 1969 C20 rear axle; what were the options?? 1969 would be a SM465. __________________ 72 C2500 LWB 402 Sierra Grande 05 Odyssey 08 Tundra



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