Stock Shackle Length? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**special-K** · 01-31-2011, 12:14 PM

GM doesn't have rear shackles any longer,not even up into the '90s...I tried...a lot. I am trying to gather whatever info on differences there may be between C/20,C/10,K/10,K/20,and C/30. They referred me to the company that supplies heavier upfit shackles for Stepvans and motorhomes "to GM".
Can some of you measure center of bolt to center of bolt and state which model you have for comparison? I always assumed they were all the same but have reason to believe that may not be true. I believe the 2wd shackles are a bit longer,making for a lower ride height. Any help is appreciated.

OldCreek · 01-31-2011, 01:15 PM

Remember, also, the front spring hanger on the rear leafs can be different. I'm not sure if it's a 2wd thing but the hanger doesn't sit lower than the frame while hang lower than the frame (4wd)...allowing for a taller ride height. Also, I think the shorter ones allow for overleafs.

Anyways, I THINK the shackles I have are all approx 4.5" eye-eye... 4wd models and some that were off of c/20-30.

**special-K** · 01-31-2011, 04:04 PM

Thanks,I'll get the measurements on what I have. I got a pair of 2wd non-GM shackles the other day and I noticed they are maybe 1" longer than the ones on my '72 K2500. They are longer,but more like 1/2",than my '85 K/5. I don't have a 2wd here to compare. Part of what I wonder is if these aftermarket shackles are the same as what GMs were. All this lead me to want to gather the facts on any differences for future reference.

**special-K** · 02-01-2011, 11:07 AM

TTT

Looking for some info.

**Tim Christian** · 02-01-2011, 07:53 PM

Hey Tim, That set I sent you came from Dave at Early Classic Enterprises and he said they came off a 1972 GMC 2-wheel drive and he has always been straight up with me. Thanks

**special-K** · 02-01-2011, 11:59 PM

Thanks Tim. I wasn't questioning what those were,but it is what sparked my interest. I figured they were all the same and plan to use these on a 4wd. They surely will work. I got to measuring what I have here ('85 4wd,'89 4wd,'72 4wd,and the 67-72 2wds I got from you) and got variations all within an inch. I just figured this was good info for leaf spring guys since they can no longer just run out and buy them from GM anymore. They can interchange but with slightly different lengths.

01-31-2011, 12:14 PM	#1
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Stock Shackle Length? GM doesn't have rear shackles any longer,not even up into the '90s...I tried...a lot. I am trying to gather whatever info on differences there may be between C/20,C/10,K/10,K/20,and C/30. They referred me to the company that supplies heavier upfit shackles for Stepvans and motorhomes "to GM". Can some of you measure center of bolt to center of bolt and state which model you have for comparison? I always assumed they were all the same but have reason to believe that may not be true. I believe the 2wd shackles are a bit longer,making for a lower ride height. Any help is appreciated. __________________ "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 ~

01-31-2011, 01:15 PM	#2
OldCreek Registered User Join Date: Jan 2007 Location: Central Coast California Posts: 1,026	Re: Stock Shackle Length? Remember, also, the front spring hanger on the rear leafs can be different. I'm not sure if it's a 2wd thing but the hanger doesn't sit lower than the frame while hang lower than the frame (4wd)...allowing for a taller ride height. Also, I think the shorter ones allow for overleafs. Anyways, I THINK the shackles I have are all approx 4.5" eye-eye... 4wd models and some that were off of c/20-30. __________________ 1972 K20 Suburban 5.7/700r4/NP205 Dana 44/H052 Sold 1972 C10 5.3L/4L60E 12bolt 5Lug - Sold 1971 K5 Blazer 6.0L LQ9 4L60E NP205 Dana 44/H052!!! 1970 K3500 1ton CrewCab 8.1L/Allison1000/NP205 Dana 60/14B!!!! - Sold 1984 K10 SWB 7.4L/4L80e/NP208 Corp 10/12 bolt Sold 1988 V30 CCLB 7.4L/TH400/NP205/Dana 60/Dana 70/3.73!!! (Sold) 2003 K2500HD 8.1/Allison1000/NP263 Last edited by OldCreek; 01-31-2011 at 01:17 PM.

01-31-2011, 04:04 PM	#3
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: Stock Shackle Length? Thanks,I'll get the measurements on what I have. I got a pair of 2wd non-GM shackles the other day and I noticed they are maybe 1" longer than the ones on my '72 K2500. They are longer,but more like 1/2",than my '85 K/5. I don't have a 2wd here to compare. Part of what I wonder is if these aftermarket shackles are the same as what GMs were. All this lead me to want to gather the facts on any differences for future reference. __________________ "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 ~

02-01-2011, 11:07 AM	#4
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: Stock Shackle Length? TTT Looking for some info. __________________ "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 ~

02-01-2011, 07:53 PM	#5
Tim Christian Senior Member Join Date: Dec 1999 Location: TN/VA Posts: 6,388	Re: Stock Shackle Length? Hey Tim, That set I sent you came from Dave at Early Classic Enterprises and he said they came off a 1972 GMC 2-wheel drive and he has always been straight up with me. Thanks

02-01-2011, 11:59 PM	#6
special-K Special Order Join Date: Nov 2004 Location: Mt Airy, MD Posts: 85,861	Re: Stock Shackle Length? Thanks Tim. I wasn't questioning what those were,but it is what sparked my interest. I figured they were all the same and plan to use these on a 4wd. They surely will work. I got to measuring what I have here ('85 4wd,'89 4wd,'72 4wd,and the 67-72 2wds I got from you) and got variations all within an inch. I just figured this was good info for leaf spring guys since they can no longer just run out and buy them from GM anymore. They can interchange but with slightly different lengths. __________________ "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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