4x4 frame

[WETOWM]

Is there any differance between a 4x4 1970 k10 frame and a frame from a 1972 4x4 k30 frame ?

[1972RedNeck]

Originally Posted by WETOWM

a 1972 4x4 k30 frame ?

Where did you get one of those?

[WETOWM]

I have not bought it yet thats what he is telling me the truck was i would think that the frames are the same 10-30

[BLAZERMAN]

K-10 and K-20 frames are the same..there were no K-30s, the only way you could get a K-30 back then was by going thru NAPCO and they would have started with a C-30 truck and converted it.

[SS Tim]

They are not the same and there were no known factory "K30" trucks for 67-72.

These are the different PICKUP TRUCK frames as I understand. Any corrections are invited.

C/10 115" COIL
C/10 115" LEAF
C/20 127" COIL
C/20 127" LEAF
C/30 133" LEAF (Longhorn C/20 & C/30)
C/30 133" LEAF (9' Stepside)

K/10 115"
K/10 / K/20 127"

[WETOWM]

So if i have a c-10 pickup 4x4 the c-20 & c-30 frames are differant?

[BLAZERMAN]

I guesse I shouldnt have used the K to referance the 4x4 since that started in 73. No they would not be the same, you could have a C/10 4X4 or a C/10 2X4 in these years as the C just denotes a custom series. A C/30 frame is about 1" taller and slightly thicker than a C/10 or C/20 frame...plus either 6" or 30" longer than the 10/20 series...confused yet? I am!

[SS Tim]

Originally Posted by WETOWM

So if i have a c-10 pickup 4x4 the c-20 & c-30 frames are differant?

This is the sticky part. "C" denotes a conventional 4x2 truck in this useage and "K" denotes a conventional 4x4. External badging does not reflect this in the fender model badge. The VIN however will. It should start out CS or CE for 4x2 and KS or KE for factory 4x4 trucks. Late truck will sometimes have C or T prefix as well (CCE or TKS are examples).

So, if you have a factory K/10 lwb then it is the same as a K/20 frame. However C/10 lwb, C/20, C/30, C/20-30 Longhorns are different and different from each other as well.

[Vintage Windmills]

Tim, are you sure the K10 and K20 lwb frames are the same? I was reviewing some literature the other night and it listed the "section modulus" of the 2wd frames as different between a lwb c10 and c20 which implies a slightly thicker frame. I will look again and see if it had the values for the 4x4's.

[SS Tim]

Originally Posted by Vintage Windmills

Tim, are you sure the K10 and K20 lwb frames are the same? I was reviewing some literature the other night and it listed the "section modulus" of the 2wd frames as different between a lwb c10 and c20 which implies a slightly thicker frame. I will look again and see if it had the values for the 4x4's.

Judd,
Very good. But yes I did review that number as well. Here is the list below. As I understand C/10 swb and K/10 swb have the same section height. C/20, K/10 lwb and K20 have the same but taller section height. C/30s and Longhorns are still taller yet. Its important to remember that even though many models have the same section height and/or modulus the rails may have different shapes and spacing.

C/10 115" 2.98
C/10 127" 2.98
C/20 127" 3.71
C/30 133" 5.05
C/20-30 Longhorns 5.05

K/10 115" 2.70
K/10 127" 3.48
K/20 127" 3.48

[Vintage Windmills]

Good info Tim, makes sense now why the GVWR is that much higher for a K10 lwb than a C10 lwb.

[SS Tim]

Originally Posted by Vintage Windmills

Good info Tim, makes sense now why the GVWR is that much higher for a K10 lwb than a C10 lwb.

Thanks, It also underscores why I prefer converting a Longhorn vs. beefing a K/20. Its more than just six inches ahead of the rear axle.