rear end question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

va_tlc · 05-11-2007, 01:09 PM

these numbers was on the ring gear 11 41 so if i divide those 2 i come up with 3.72 something rounded off i guess it be a 3.73 right? ill get a pic of it as soon as i get it out from under the donor. man i searched everywhere for this rear a 14 bolt 8 lug 3/4 ton. i called alot of junk yards nope no luck. so all else fails i walk across my road to the friends house and there it sits . goes to show me sometimes its right under our nose. ill get some pics of his ole trucks.

1969k10stepside · 05-11-2007, 01:16 PM

Yep.Thats a 3:73 ratio

va_tlc · 05-11-2007, 01:37 PM

thanks dustin. thats a pretty good score for free huh. now i jus gotta buy the front ring an pinion . i gotta hurry and get the rear b4 the snakes come out. man i hate snakes this prevents me from lots of junk yards in summer

1969k10stepside · 05-11-2007, 01:43 PM

So,are you going to put that rear under the 72?If you do...you are going to have to move the shock mounts and spring perches.
I like the 3:73s in all my 4wds.The work truck 69 4wd is going to be upped to a 3/4 ton though so its getting lower gears (4:11s) so I can use it to tow trailers and haul heavy loads.

va_tlc · 05-11-2007, 04:28 PM

yea dustin im gonna put the 14 bolt in there . only because i called everywhere looking for a ring an pinion for the one in there i belive its a 72 ho is what randys ring and pinion said. and he went on to say he dont have any and probally only way ill find a 3.73 is from someone who has one of these rear ends. so the guy next door had this 14 bolt in a 75 3/4 ton. said i could have it so i took the kubota and pushed my wife down the road with it, i got one side loose today and the other side is soaking now with wd 40.... yea i thought i was gonna have to buy new perches and weld em in and move the shock mounts. plus now im gonna have to buy a 3.73 for the front also. about how much ya think that will be , i have a friend who can set it up, hope someone is in need of a matching set my rear with 4.55 gears and front. guess ill have to post it later.

va_tlc · 05-11-2007, 04:48 PM

anyone know what this rear is called? its 14 bolt, but thats all i know its out of a 75 3/4 2 wd . thanks

va_tlc · 05-11-2007, 04:52 PM

i know how everyone likes pics... heres the donor. i gotta find a rear to put back in it to return it to the neighbor. he jsut wants to be able to move it around to mow, gotta take my camera when i go back and get yalls some pics of his mini chevy grave yard, like 3 or 4 54 chevy trucks.. 1 72 with a scalped top...

1969k10stepside · 05-11-2007, 04:54 PM

It's just called a 14 bolt.The stock 3/4 ton rear diff for the 67-72s was the HO52,IIRC. I might be able to hook you up with some 3:73s for the front as soon as my 69 4wd goes 3/4 ton.My stock front ring gear for the 71 was shot and I bought a different ring & pinion that was 3:73s for $50 shipped.But they did come priority mail so that does give you an idea on the costs for a used 3:73 ring & pinion

va_tlc · 05-11-2007, 05:06 PM

ok dustin sounds great. ill check with my friend the one whos gonna set it up for me. he said he thinks he has a few 3.73 also . so i may be able to trade him the 4.55 rear and front for his gear and some labor. bad thing is iv put all new brakes and wheel cylinders on the rear im taking out.... kinda doubt it will fit the 14 bolt huh? ohh well since i got the reat for free guess it wont hurt to buy new barkes and things.. just hope the drums are good. i check on the drums for the 12 bolt and rears are 133 each ouch....

**special-K** · 05-11-2007, 05:28 PM

What rear did you have in there?What year frame did you use on your truck?Were the axles the ones that were on that frame?I know it`s 3/4t 8-lug.

va_tlc · 05-12-2007, 10:46 AM

yea tim as far as i know there the same ones that came in the truck the frame is a 69 0r 70 model drums all the way around, the guy at randys ring and pinion asked if the rear has bolts on both sides, kinda like you could take the gears out each way and yes thats the one i have so he went on to say it was a ho 72, and he didnt and couldnt get a ring gear for it, the front is a 44 i belive, the ratio of those are 4.55 still had the metal tag on the front punkin

old Chevy guy · 05-12-2007, 06:05 PM

Are you looking for the rear end that the whole center comes out the front of? Kind of like an old 9 inch ford only the back cover comes off to? If so I have about half a dozen of those layin around here but Im not sure about the gear ratio's is it marked on the housing somewhere or what? Im in rhode Island but I have a Brother in law thats do to come up here soon and he lives in Front Royal Va is that anywhere near you?

va_tlc · 05-12-2007, 09:32 PM

yea front royal is about 1 hour from me, but i belive from what iv heard thats its very hard to find parts for these rears, so im just gonna swap out to this 75 rear should be alil easier to find parts for. and yes if you take the rear cover off and jack the truck up so u can spin the tires the numbers are stamped on the ring gear, just write down all those numbers and post here someone will tell ya what you have, i was told most of these rears are geared pretty low,

old Chevy guy · 05-13-2007, 06:44 PM

What gears are in that truck now ? I get the easier to find parts but are you wanting to change the ratio or are you just settling for what you have in your donar truck. Im sure you know that you can bolt the center chuck in from a diffrent rear end like your old one with no fuss. I counted up today and I have at least7 rears with that chuck I know ones a4/11 and I think ones 3/73. let me know what you need and if you change your mind about swappin the whole thing out mabey we can hook something up.

va_tlc · 05-13-2007, 07:56 PM

thanks alot chevy guy, wish id talked with you earlier cause yes i was just wanting to change ratio, the truck now has 4.55 gears which is way to low for my use, but as of right now iv already pulled the donor rear and its a 3.73 so ill just have to move my spring perches and shock mounts, guess i cant complian i got the rear for free, are you postive you have a 3.73 gear? 12 bolt?

old Chevy guy · 05-15-2007, 10:44 PM

Im not absolutly positive but one day I was looking at the glove box tags on some trucks I have stored about 12 miles up the road and I think one was. If you were interested I could find out for sure. I was looking because I was wanting to upgrade a 69 k10 I have and I was thinking of doing the same thing as you.Then I thought about trying to find an old rear to match a new front so as not to have to cut and weld. I have two pairs of newer axles,but I didnt know the ratio of the front ones I had so I was gonna try to find out when I found a 69 K 20 rusty but good driveline to be a doner for 200 bucks instead. strangly enogh I saw a69-72 Gmc k 20 in a field I inquired about the same day that lady said she would get back to me . then I bought the K 20 later that day and that guy told me his brother had another one Id looked at afew years ago that was probly for sale too! I may look at that one later for parts too.

05-11-2007, 01:09 PM	#1
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	rear end question these numbers was on the ring gear 11 41 so if i divide those 2 i come up with 3.72 something rounded off i guess it be a 3.73 right? ill get a pic of it as soon as i get it out from under the donor. man i searched everywhere for this rear a 14 bolt 8 lug 3/4 ton. i called alot of junk yards nope no luck. so all else fails i walk across my road to the friends house and there it sits . goes to show me sometimes its right under our nose. ill get some pics of his ole trucks. __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4

05-11-2007, 01:16 PM	#2
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: rear end question Yep.Thats a 3:73 ratio

05-11-2007, 01:37 PM	#3
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	Re: rear end question thanks dustin. thats a pretty good score for free huh. now i jus gotta buy the front ring an pinion . i gotta hurry and get the rear b4 the snakes come out. man i hate snakes this prevents me from lots of junk yards in summer __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4

05-11-2007, 01:43 PM	#4
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: rear end question So,are you going to put that rear under the 72?If you do...you are going to have to move the shock mounts and spring perches. I like the 3:73s in all my 4wds.The work truck 69 4wd is going to be upped to a 3/4 ton though so its getting lower gears (4:11s) so I can use it to tow trailers and haul heavy loads. Last edited by 1969k10stepside; 05-11-2007 at 01:45 PM.

05-11-2007, 04:28 PM	#5
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	Re: rear end question yea dustin im gonna put the 14 bolt in there . only because i called everywhere looking for a ring an pinion for the one in there i belive its a 72 ho is what randys ring and pinion said. and he went on to say he dont have any and probally only way ill find a 3.73 is from someone who has one of these rear ends. so the guy next door had this 14 bolt in a 75 3/4 ton. said i could have it so i took the kubota and pushed my wife down the road with it, i got one side loose today and the other side is soaking now with wd 40.... yea i thought i was gonna have to buy new perches and weld em in and move the shock mounts. plus now im gonna have to buy a 3.73 for the front also. about how much ya think that will be , i have a friend who can set it up, hope someone is in need of a matching set my rear with 4.55 gears and front. guess ill have to post it later. __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4

05-11-2007, 04:48 PM	#6
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	Re: rear end question anyone know what this rear is called? its 14 bolt, but thats all i know its out of a 75 3/4 2 wd . thanks __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4

05-11-2007, 04:52 PM	#7
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	Re: rear end question i know how everyone likes pics... heres the donor. i gotta find a rear to put back in it to return it to the neighbor. he jsut wants to be able to move it around to mow, gotta take my camera when i go back and get yalls some pics of his mini chevy grave yard, like 3 or 4 54 chevy trucks.. 1 72 with a scalped top... __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4

05-11-2007, 04:54 PM	#8
1969k10stepside Registered User Join Date: Mar 2006 Location: USA Posts: 21,020	Re: rear end question It's just called a 14 bolt.The stock 3/4 ton rear diff for the 67-72s was the HO52,IIRC. I might be able to hook you up with some 3:73s for the front as soon as my 69 4wd goes 3/4 ton.My stock front ring gear for the 71 was shot and I bought a different ring & pinion that was 3:73s for $50 shipped.But they did come priority mail so that does give you an idea on the costs for a used 3:73 ring & pinion Last edited by 1969k10stepside; 05-11-2007 at 05:21 PM.

05-11-2007, 05:06 PM	#9
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	Re: rear end question ok dustin sounds great. ill check with my friend the one whos gonna set it up for me. he said he thinks he has a few 3.73 also . so i may be able to trade him the 4.55 rear and front for his gear and some labor. bad thing is iv put all new brakes and wheel cylinders on the rear im taking out.... kinda doubt it will fit the 14 bolt huh? ohh well since i got the reat for free guess it wont hurt to buy new barkes and things.. just hope the drums are good. i check on the drums for the 12 bolt and rears are 133 each ouch.... __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4

05-11-2007, 05:28 PM	#10
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,852	Re: rear end question What rear did you have in there?What year frame did you use on your truck?Were the axles the ones that were on that frame?I know it`s 3/4t 8-lug. __________________ "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 ~

05-12-2007, 10:46 AM	#11
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	Re: rear end question yea tim as far as i know there the same ones that came in the truck the frame is a 69 0r 70 model drums all the way around, the guy at randys ring and pinion asked if the rear has bolts on both sides, kinda like you could take the gears out each way and yes thats the one i have so he went on to say it was a ho 72, and he didnt and couldnt get a ring gear for it, the front is a 44 i belive, the ratio of those are 4.55 still had the metal tag on the front punkin __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4

05-12-2007, 06:05 PM	#12
old Chevy guy Registered User Join Date: Apr 2007 Location: Foster Rhode Island Posts: 1,176	Re: rear end question Are you looking for the rear end that the whole center comes out the front of? Kind of like an old 9 inch ford only the back cover comes off to? If so I have about half a dozen of those layin around here but Im not sure about the gear ratio's is it marked on the housing somewhere or what? Im in rhode Island but I have a Brother in law thats do to come up here soon and he lives in Front Royal Va is that anywhere near you?

05-12-2007, 09:32 PM	#13
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	Re: rear end question yea front royal is about 1 hour from me, but i belive from what iv heard thats its very hard to find parts for these rears, so im just gonna swap out to this 75 rear should be alil easier to find parts for. and yes if you take the rear cover off and jack the truck up so u can spin the tires the numbers are stamped on the ring gear, just write down all those numbers and post here someone will tell ya what you have, i was told most of these rears are geared pretty low, __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4

05-13-2007, 06:44 PM	#14
old Chevy guy Registered User Join Date: Apr 2007 Location: Foster Rhode Island Posts: 1,176	Re: rear end question What gears are in that truck now ? I get the easier to find parts but are you wanting to change the ratio or are you just settling for what you have in your donar truck. Im sure you know that you can bolt the center chuck in from a diffrent rear end like your old one with no fuss. I counted up today and I have at least7 rears with that chuck I know ones a4/11 and I think ones 3/73. let me know what you need and if you change your mind about swappin the whole thing out mabey we can hook something up.

05-13-2007, 07:56 PM	#15
va_tlc Registered User Join Date: Nov 2005 Location: VIRGINIA Posts: 905	Re: rear end question thanks alot chevy guy, wish id talked with you earlier cause yes i was just wanting to change ratio, the truck now has 4.55 gears which is way to low for my use, but as of right now iv already pulled the donor rear and its a 3.73 so ill just have to move my spring perches and shock mounts, guess i cant complian i got the rear for free, are you postive you have a 3.73 gear? 12 bolt? __________________ 1969 rs 1966fastback 1969swbc/10 2006gt 1972swb4x4



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05-15-2007, 10:44 PM	#16
old Chevy guy Registered User Join Date: Apr 2007 Location: Foster Rhode Island Posts: 1,176	Re: rear end question Im not absolutly positive but one day I was looking at the glove box tags on some trucks I have stored about 12 miles up the road and I think one was. If you were interested I could find out for sure. I was looking because I was wanting to upgrade a 69 k10 I have and I was thinking of doing the same thing as you.Then I thought about trying to find an old rear to match a new front so as not to have to cut and weld. I have two pairs of newer axles,but I didnt know the ratio of the front ones I had so I was gonna try to find out when I found a 69 K 20 rusty but good driveline to be a doner for 200 bucks instead. strangly enogh I saw a69-72 Gmc k 20 in a field I inquired about the same day that lady said she would get back to me . then I bought the K 20 later that day and that guy told me his brother had another one Id looked at afew years ago that was probly for sale too! I may look at that one later for parts too.

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