for sale 1970 3.73 posi rearend. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

468BIGBLOCK · 08-18-2003, 08:32 PM

coil spring 6 lugger i have pulled the cover it could use cleaned up and new brakes in n.e arkansas 72450/ $275.00

68_c10_on20s · 08-19-2003, 01:57 AM

can you tell me if all the seals are ok and would my 5 lug axles fit it in that i have a 68 with a 72 3:08 gear rear end but been lookin for a 73 posi but i have 5 lug i can drive to you to pick up and my rear will cost me 800 for new posi and gear...Steve

468BIGBLOCK · 08-20-2003, 10:51 PM

i dont know if ya can change them or not someone around here prolly knows, it does need new seals/later dude!

69c10stepside · 08-20-2003, 11:59 PM

Here is what I know.. Gm truck 12 bolt rearends can all use either 5 lug or 6 lug rear ends. However, 2.73 - 3.42 gear ratios compared to 3.73 - 4.56 ( maybe just 3.73 - 4.10 ) use a different carrier. Hope this helps.

68_c10_on20s · 08-21-2003, 09:28 AM

yeah but would the axles be the same? i dont see why not and 468 you still have the rear end? maybe willing to meet a little closer to me im in Houston

jmanz69 · 08-21-2003, 11:16 AM

The 67-69 axles are a different width than the 70-72 axles. Your 5 lug axles will fit in the 70 housing cuz that was the only year they made the wider housing with the 6 lug axles. It makes no difference what gears are in it, they will slide right in. If you want to change the gears, you can use any 12 bolt truck carrier with the CORRECT ring and pinion. 3.73 and up use the 4 series carrier, while 3.08 will use the 3 series carrier. If it's a 70 axle, it most likely has 3.73 gears. If you decide to swap gears and carriers, have it done professionally. If set up wrong, you WILL destroy your gears, carrier, and housing. Rear gears are not something to cheap out on, anda it's not just a simple bolt in swap.

boraxman · 08-21-2003, 03:34 PM

Quote:

Originally posted by jmanz69
The 67-69 axles are a different width than the 70-72 axles. Your 5 lug axles will fit in the 70 housing cuz that was the only year they made the wider housing with the 6 lug axles. It makes no difference what gears are in it, they will slide right in. If you want to change the gears, you can use any 12 bolt truck carrier with the CORRECT ring and pinion. 3.73 and up use the 4 series carrier, while 3.08 will use the 3 series carrier. If it's a 70 axle, it most likely has 3.73 gears. If you decide to swap gears and carriers, have it done professionally. If set up wrong, you WILL destroy your gears, carrier, and housing. Rear gears are not something to cheap out on, anda it's not just a simple bolt in swap.

Ive herd others say that 70's went wider mid year. True or false?

jmanz69 · 08-21-2003, 03:53 PM

might be, I have heard that all 70 axles were the wider ones. You can measure to see what you have. Measure the housing on a 67-69 from flange to flange, then have someone measure a 70 housing from flange to flange. Just to be sure.

**1970 CST Short Wide** · 08-21-2003, 03:59 PM

My 70 was originally 6 lug. I bought a 71 5 lug parts truck and the axels matched perfectly

69c10stepside · 08-21-2003, 08:01 PM

In my lmc catalog, the part number for a 70 year model 1/2 2wd axle is the same part number as the 4x4 pickup and blazers.. sounds like 70 - until they stopped making 12bolts

468BIGBLOCK · 08-21-2003, 08:06 PM

i can measure this one and see if its the same.

JimKshortstep4x4 · 08-22-2003, 08:41 AM

I would suggest measuring the 70 rear end as some had longer axles and some has the shorter axles. The longer axle rear ends are 67 1/2" between the backing plates, approximately.

Jim

08-18-2003, 08:32 PM	#1
468BIGBLOCK MEMBER OF THE JUNK MAN CLUB Join Date: Jul 2001 Location: paragould arkansas 72450 Posts: 425	for sale 1970 3.73 posi rearend. coil spring 6 lugger i have pulled the cover it could use cleaned up and new brakes in n.e arkansas 72450/ $275.00

08-19-2003, 01:57 AM	#2
68_c10_on20s Registered User Join Date: Aug 2002 Location: Waxahachie TX Posts: 773	posi can you tell me if all the seals are ok and would my 5 lug axles fit it in that i have a 68 with a 72 3:08 gear rear end but been lookin for a 73 posi but i have 5 lug i can drive to you to pick up and my rear will cost me 800 for new posi and gear...Steve __________________ 93 Fleet Budget Build http://s150.photobucket.com/albums/s...zted71/hoopty/

08-20-2003, 11:59 PM	#4
69c10stepside Large Member Join Date: Jun 2002 Location: Northwest Arkansas Posts: 747	Here is what I know.. Gm truck 12 bolt rearends can all use either 5 lug or 6 lug rear ends. However, 2.73 - 3.42 gear ratios compared to 3.73 - 4.56 ( maybe just 3.73 - 4.10 ) use a different carrier. Hope this helps. __________________ 1989 GMC C1500 ECSB 1972 Gmc Jimmy 1972 Chevy C10 SWB Sold

08-21-2003, 09:28 AM	#5
68_c10_on20s Registered User Join Date: Aug 2002 Location: Waxahachie TX Posts: 773	axles yeah but would the axles be the same? i dont see why not and 468 you still have the rear end? maybe willing to meet a little closer to me im in Houston __________________ 93 Fleet Budget Build http://s150.photobucket.com/albums/s...zted71/hoopty/

08-21-2003, 03:59 PM	#9
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,192	My 70 was originally 6 lug. I bought a 71 5 lug parts truck and the axels matched perfectly __________________ 1970 CST LS 1 6 speed Ford 9 inch Detroit Tru Track, Dakota Didgital, Vintage Air, QA1 Coil Overs Front & Rear Lots of FUN 2013 GMC PU, Oldest Son 71 GMC LWB. QA1 Suspension, Angry SB. Youngest Son 2017 Toyota SUV Daughters car 2018 Traverse , Wife’s Ride Pittsburg Ca 94565

08-20-2003, 10:51 PM	#3
468BIGBLOCK MEMBER OF THE JUNK MAN CLUB Join Date: Jul 2001 Location: paragould arkansas 72450 Posts: 425	i dont know if ya can change them or not someone around here prolly knows, it does need new seals/later dude!

08-21-2003, 11:16 AM	#6
jmanz69 Careful, they attack... Join Date: Aug 2001 Location: Waterford, MI, USA Posts: 1,107	The 67-69 axles are a different width than the 70-72 axles. Your 5 lug axles will fit in the 70 housing cuz that was the only year they made the wider housing with the 6 lug axles. It makes no difference what gears are in it, they will slide right in. If you want to change the gears, you can use any 12 bolt truck carrier with the CORRECT ring and pinion. 3.73 and up use the 4 series carrier, while 3.08 will use the 3 series carrier. If it's a 70 axle, it most likely has 3.73 gears. If you decide to swap gears and carriers, have it done professionally. If set up wrong, you WILL destroy your gears, carrier, and housing. Rear gears are not something to cheap out on, anda it's not just a simple bolt in swap.

08-21-2003, 03:53 PM	#8
jmanz69 Careful, they attack... Join Date: Aug 2001 Location: Waterford, MI, USA Posts: 1,107	might be, I have heard that all 70 axles were the wider ones. You can measure to see what you have. Measure the housing on a 67-69 from flange to flange, then have someone measure a 70 housing from flange to flange. Just to be sure.

08-21-2003, 08:01 PM	#10
69c10stepside Large Member Join Date: Jun 2002 Location: Northwest Arkansas Posts: 747	In my lmc catalog, the part number for a 70 year model 1/2 2wd axle is the same part number as the 4x4 pickup and blazers.. sounds like 70 - until they stopped making 12bolts __________________ 1989 GMC C1500 ECSB 1972 Gmc Jimmy 1972 Chevy C10 SWB Sold

08-21-2003, 08:06 PM	#11
468BIGBLOCK MEMBER OF THE JUNK MAN CLUB Join Date: Jul 2001 Location: paragould arkansas 72450 Posts: 425	i can measure this one and see if its the same.

08-22-2003, 08:41 AM	#12
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	I would suggest measuring the 70 rear end as some had longer axles and some has the shorter axles. The longer axle rear ends are 67 1/2" between the backing plates, approximately. Jim



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