K10 rear springs q and a

[Blackfyre77]

Ok guys, im at a loss please answer if you can. My 1970 k10, it could have come with 52 or 56 inch rear springs originally, correct? I have 2 frames one a k10 and one a k20 both have 52 inch springs, mine however under my truck has 56 inch springs. Im looking to buy a lift kit and was about to order it when i realized the kit claims to fit k20 trucks, but does not say it fits k10s. I only measured my springs to see though because i read somewhere they could be either size. My question is 56 inch springs DID come on k10s, right? I told skyjacker it was a k10 when asking about the kit and was not corrected.... the kit im looking at is a c260aksd-m - 6in. (Skyjacker) Thanks guys. Im not crazy, right?

[Mike C]

I don't think the 56" spring ever came on a 69-72 K series truck. They were a '73 and up addition IME. I'm interested to see what others say.

[Stocker]

^^ That sounds right to me. Stock spring length is 52" and K10 & K20 packs are interchangeable as far as fit. Thickness & load capacity will vary of course.

OP, if your truck has 56" springs, they have been swapped in by a previous owner.

[Blackfyre77]

Ok, so i called skyjacker again to ask about this. They say that 1969-72 used 52 or 56 on k10s, but, 1967-68 used a different length unknown to the guy i was talking to. He said they did not make a spring for those two years because with thier age and limited year range it wouldnt be profitable for them. But 56s did according to them come on some 69-72s, he says it is more or less still like a big 10 or heavy half (towing package) kind of deal, it wasnt to get around emissions like those, but still used the larger springs. Can anyone tell me what length spring was used on the rear in 67-68? Im just curious.

[57taskforce]

Originally Posted by Blackfyre77

Ok, so i called skyjacker again to ask about this. They say that 1969-72 used 52 or 56 on k10s, but, 1967-68 used a different length unknown to the guy i was talking to. He said they did not make a spring for those two years because with thier age and limited year range it wouldnt be profitable for them. But 56s did according to them come on some 69-72s, he says it is more or less still like a big 10 or heavy half (towing package) kind of deal, it wasnt to get around emissions like those, but still used the larger springs. Can anyone tell me what length spring was used on the rear in 67-68? Im just curious.

I don’t think that is correct. Im confident all 67-72 long bed 4x4 frames whether they be 1/2 or 3/4 ton are functionally identical (there may be some very small year to year changes like the 72 spring stops welded/ bolted to the drivers front spring mounts etc). 67-68 did use different spring widths that is true but I’m pretty certain the lengths were the same 52” .. I’ve never seen a 67-72 with 56s, it’s been proven on here several times that the longbed frames are identical. Ie. no longer/ shorter spring mount locations. I would Stick to the info of this site versus what some manufactures are claiming. For the 67-72s the spring capacity is determined but the number of leaves in the pack not the length of the spring.

[Blackfyre77]

I do trust what im told on this site, im just confused, my spring perches are factory riveted to my frame still in a location 4 inches wider than the other k10 frame i have, the other chassis i have is from a 1971 or 72, has 52 inch springs my truck is a 1970 and the springs that are on it measure 57-1/2. I know my trucks chasis is at least a 1970 chasis because it has drum front brakes and the dana 44 front pulls numbers reading 1969 for manufacture. So, it should be a 69 or 70. My truck is titled as 1970, not that things couldnt have been changed over 48 years. You are saying the spring WIDTH was the difference in 67 and 68? The lengths remained the same? My frame, also, is identical to the 71 or 72 that i have in most other ways, with the exception of no clearance dimples where the steering gear mounts, forged steel front - front leaf spring mounts instead of stamped, and the spacing of the rear leaf mounts. ALL mounts are still factory riveted in location. Im CERTAIN my frame is a 67-72 frame, and im sure it requires a spring longer than 52 inches, im just trying to be certain at this point i dont have a 67 or 68 frame which takes the springs that arent manufactured in lift form.

[Blackfyre77]

*footnote* i also have a k20 chassis which has 52 inch springs and the perches in the same location as the 71-72 k10 chassis i own. So, 1 of 3 has the longer springs. A k10 and k20 with 52" and my truck as described.

[57taskforce]

Originally Posted by Blackfyre77

I do trust what im told on this site, im just confused, my spring perches are factory riveted to my frame still in a location 4 inches wider than the other k10 frame i have, the other chassis i have is from a 1971 or 72, has 52 inch springs my truck is a 1970 and the springs that are on it measure 57-1/2. I know my trucks chasis is at least a 1970 chasis because it has drum front brakes and the dana 44 front pulls numbers reading 1969 for manufacture. So, it should be a 69 or 70. My truck is titled as 1970, not that things couldnt have been changed over 48 years. You are saying the spring WIDTH was the difference in 67 and 68? The lengths remained the same? My frame, also, is identical to the 71 or 72 that i have in most other ways, with the exception of no clearance dimples where the steering gear mounts, forged steel front - front leaf spring mounts instead of stamped, and the spacing of the rear leaf mounts. ALL mounts are still factory riveted in location. Im CERTAIN my frame is a 67-72 frame, and im sure it requires a spring longer than 52 inches, im just trying to be certain at this point i dont have a 67 or 68 frame which takes the springs that arent manufactured in lift form.

You have my attention!! Can you post some pictures of what you’ve got? The frame not being dimpled makes me wonder if it’s a 67. Have you tried to dig for the partial vin stamped on the drivers frame rail by the steering box? some of the earlier trucks don’t have that stamping.

[palallin]

FWIW, I measured my '69 today, and the springs are 52". The springs are not original, but the hangers are.