1974 C30 Suspension help

[1974 Chevy C30]

I have a 1974 c30 that was converted to a 4x4, so its basically a K30. Im looking into buying a new suspension/lift kit but all of the kits say they fit c/k 10, and 20's, but say they dont fit on C30's. Should i order everything seperate? Or buy a K20 kit and K20 mounts. Thanks

 

[Craig 85]

Some picture would help. The front of the K10-30's are fairly similar, but there are some differences. Do you have a D60 like me or a D44 or Corp 10 bolt? The 30 rears have some differences too. The first photo is my '85 K30 SRW. The C30 and K30 rear spring hangers are different than 1/2 and 3/4 ton. They move the springs closer to the frame and the shocks are reversed. Also "K" hangers are longer. The rear shocks on a 30 series are longer due to the reversed mounts. I have a 3" lift, but I used a shock for a 4-6" lift on a K20 in the rear.

The 30 frames are 2" taller than the K10/20 frame. Here a comparison. My old gray '79 K15 had a 4" lift with 33's. My '85 K30 has a 3" lift and 33's, but it is an inch taller at the body line than the '79.

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[1974 Chevy C30]

Pretty sure i got a GM 10 bolt on the front but correct me if im wrong, It has GM 7 and 14030376 Stamped on it. And i'll be able to get better pictures of my leaf springs tomorrow. I have 56 inch long leaf springs in the back, 8 pack and on the front im pretty sure its a 48 inch 3 pack. Heres a couple pictures of the front axle.

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[bucket]

There's a few clues there that help determine what you have. Specifically the front shock mounts. It is an '81-'87 frame. Based on the 56" rear springs, probably not a K10 frame. If the rear shocks are mounted outboard of the frame rails, it's a K20. If they are mounted inboard of the frame, it's a K30 frame.

But the front axle is a 10bolt, so right now I'm betting it's a K20 and has a 14-bolt, semi floating rear axle.

 

[1974 Chevy C30]

So the last owner did a body swap? And the shock mounts are mounted outboard of the frame rails. So k20, and it is a 14 bolt rear axle. So now that i know that, should i shop for suspension parts for an 81-87 K20?

 

[bucket]

So the last owner did a body swap? And the shock mounts are mounted outboard of the frame rails. So k20, and it is a 14 bolt rear axle. So now that i know that, should i shop for suspension parts for an 81-87 K20?

It would seem so, and yes.

I'm curious, what engine/trans/t-case combo do you have?

 

[1974 Chevy C30]

I have a 350, a sm465 4 speed, and a 208 transfer case. And thanks, good to know about the frame and what i should order.

 

[bucket]

I have a 350, a sm465 4 speed, and a 208 transfer case. And thanks, good to know about the frame and what i should order.

465/208 would be an '81-up combo as well. If you have a hydraulic clutch actuation, that would signify '85-up.

 

[1974 Chevy C30]

Dang I did not know that, and I dont have a hydraulic clutch.

 

[PrairieDrifter]

Dang I did not know that, and I dont have a hydraulic clutch.

Chances are someone just swapped the front clip, it's a popular swap. Have you checked your vin? Do you have blade or tube style fuses?

 

[1974 Chevy C30]

I have tube fuses and the vin says 74' c30. The last owner rigged everything to just barely work. So im trying to fix it all again haha.

 

[PrairieDrifter]

I have tube fuses and the vin says 74' c30. The last owner rigged everything to just barely work. So im trying to fix it all again haha.

Gotcha. Definitely a frame swap then.

 

[bucket]

I believe frame swaps are becoming even more common than they used to be. And there's nothing wrong with that at all, imho, so don't think anything less of the truck than you did before. Now that you have figured out what you actually have, getting parts and figuring build plans will be much easier.

 

[1974 Chevy C30]

I agree, My frame is completely solid so im ok with it. Im glad you were able to help me cause I would be so confused trying to order parts. I was looking for suspension kits and stuff for a c30, and was super confused why my springs were different. Thanks for the help!

 

[68post]

Max, are you replacing the front springs also ? Because your existing springs are distorted.
Are those new Dick Cepek tires ? (just bought some but not mounted yet)