GMC rear springs


Hi all just though someone might know if I could put 1 Ton springs under a 1/2 Ton I will not be loading this truck with alot of weight but my 3/4 Ton and soon to be 1Ton will be use for the hard work but I need to replace the springs on this 1/2 ton because one is broken . This would give me a spare Thanks Dave

75 Addict
I think it might be just as easy to have your existing springs repaired (replace the broken leaf(s) and at the same time, perhaps add a leaf or two) rather than yank everything out & start over. I don't know about your area, but around here there are a few good spring shops - one place to inquire about spring service/shops is at a heavy truck repair garage.

Also, putting a full 1-ton set of springs under the 1/2-ton will make it ride r-e-a-l rough :eek: unless you do load it down with a lot of weight.

Just a thought!


Thanks Rob I will not be driving the truck only in the winter for plowing and I thought that I`m trying to upgrade to one ton trucks so if I start putting 1 ton equiment on when I need to replace parts this will be a parts truck or spare truck when . thank alot


Senior Member
Fairbanks AK
Measure them from eye to eye first and make sure they're the same size. I thought that GM made two lengths, 52" and 56" I THINK but am not sure. I'd double check that first though. You will need some different U bolts as Dino pointed out. Any parts store should be able to help out there.

75 Addict
MTCK - I have heard the same thing on the 2 different lengths, although I'm not sure what the applications were. Measure beforehand!

Dave - having things "common" between your trucks is a good idea. Keep the good leaves out of your old 1/2 ton springs after the swap just in case you need to repair or add to any of your spring packs. If they're getting tired, the bushings in the 1-ton springs may as well be replaced while it's easy to do so.


Junior Member
Pittsburgh, PA
I thought the 1-ton perches and springs were wider than 1/2 and 3/4 ton perches and springs.

I am looking at a '81 K30 and was wandering if I could do something to soften the suspension on a budget. I was thinking of putting half ton springs on the 1 ton truck. What do ya think?