1/2 ton and 3/4 frames???

[ecgate]

Are 1967-1972 chevy 1/2 ton and 3/4 ton frames the same?

[SS Tim]

The frames are not the same except the K10 LWB and K20. 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, 9' Stepside)

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

Then there are changes for the core support between 67-68 and 69-72 trucks. 67 and I think 68 frames are not clearanced for the intergral power steering box.

Plus all of this has variations for manual or automatic transmissins and V-8 or I-6 engines.

[c10srule]

couldnt say for sure, but the only dif. i saw was extra bracing and i believe the rear cab mounts sit lower,

[bugmasta]

Some parts are the same some parts are not. I have converted a 68 c20 to a c10 with a 72 c10 parts trucks. So I know at least the suspensions components are all interchangeable. Only exception was I ordered conversion drop spindles from ece for the front but used all the brake components off the parts truck.
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[71chevswb]

Originally Posted by SS Tim

The frames are not the same except the K10 LWB and K20. 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, 9' Stepside)

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

Then there are changes for the core support between 67-68 and 69-72 trucks. 67 and I think 68 frames are not clearanced for the intergral power steering box.

Plus all of this has variations for manual or automatic transmissins and V-8 or I-6 engines.

Would there also be a C/10 127" COIL and C/10 127" LEAF in your list?


I thought C/10's and C/20 have different thickness of frames?? Not sure though.


**Are C/10 115" COIL and C/10 115" LEAF frames different? If so, how? Can a 1971 c/10 115" leaf truck be converted to coil from a 1972 c/10 115" coil truck?
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[SS Tim]

Originally Posted by 71chevswb

Would there also be a C/10 127" COIL and C/10 127" LEAF in your list?


I thought C/10's and C/20 have different thickness of frames?? Not sure though.


**Are C/10 115" COIL and C/10 115" LEAF frames different? If so, how? Can a 1971 c/10 115" leaf truck be converted to coil from a 1972 c/10 115" coil truck?

Thanks for catching that, it was cut and pasted right out.
There are differences in frame height and section width as well as thickness changes. The rail shape is different as too. The coil trucks have the frame pushed out over the axle for the spring cup in addition to crossmember changes. Below is an illustration to help visualize it.


The frames are not the same except the K10 LWB and K20. These are the different PICKUP TRUCK frames as I understand. Referenced from the GM 1970 truck specifications book. Any corrections are invited.

C Blazer COIL
C Blazer LEAF
C/10 115" COIL
C/10 115" LEAF
C/10 127" COIL
C/10 127" LEAF
C/20 127" COIL
C/20 127" LEAF
C/30 133" LEAF (Longhorn C/20 & C/30, 9' Stepside)
C/30 157" LEAF (Chassis Cab only)

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

The frame section and modulus numbers, 39k psi carbon steel through C30s. Note the increased section height, flange width and thickness changes of the frame as the series step up.

C Blazer
C10 115
C10 127 6.04" height 2.53" flange width 0.156" thick 2.98 section modulus

C20 127 6.11" height 2.46" flange width 0.194" thick 3.71 section modulus

C20/30 133 (Longhorns) 7.20" height 2.77" flange width 0.194" thick 5.05 section modulus

C30 157 8.18" height 2.97" flange width 0.224" thick 7.29 section modulus


K Blazer
K10 115 6.02" height 2.71" flange width 0.141" thick 2.70 section modulus

K10 127
K20 127 6.09" height 2.75" flange width 0.186" thick 3.48 section modulus

[DaHos]

Well ok then.........guess they are different........