1/2 and 3/4 ton differences

[Sachmo]

I'm having a hard time finding the differences between the 83 k10 an k20. Info please!

 

[crazy4offroad]

K10 had 10 bolt rear, K20 had 14 bolt full-floater. Up front not much difference in axles, other than K20 had 8-lug outers and a little bigger brakes. Otherwise, same ole 10-bolt front axle. Some K20s probably have beefier leaf springs all around, and the rears are 56" instead of K10's 52" Hope this helps!

 

[Sachmo]

Thank you, exactly what I was looking for!

 

[bucket]

By then, many K20 trucks didn't get the 14 bolt full float rear, they could also have the 14 bolt semi float rear. If an auto trans, the K20 would have a TH400, while the K10 would have a TH350 or a 700R4. Also, many K20 trucks had slightly thicker frame rails depending on how the truck was optioned.

 

[HotRodPC]

And a K20 could have EITHER 52 or 56 inch rear springs depending on it's suspension package.
C10 and K20 were the only models that could have either or. Both C10, C20, K10 and K20 are all frame punched for either 52 or 56 inch springs that I've seen, so it's easy to change too. I'll be going 56in springs on my K10 that's going to be getting 56 in springs from the rear of a C20.

And noone as of yet confirmed that K20 has thicker frame rails than K10.

 

[bucket]

And noone as of yet confirmed that K20 has thicker frame rails than K10.

It's in the old GM frame spec charts. There were several different thicknesses used between C10-30, K10-30, Burbs and Blazers. Some years all K20's had slightly thicker rails than a K10, but other years it depended on options like Camper Special.

 

[HotRodPC]

It's in the old GM frame spec charts. There were several different thicknesses used between C10-30, K10-30, Burbs and Blazers. Some years all K20's had slightly thicker rails than a K10, but other years it depended on options like Camper Special.

Anyone have access to those charts?

 

[bucket]

Anyone have access to those charts?

I've seen scans of different charts posted before on the internet, but I haven't had any luck finding them again. Some of the charts are hard to read because the frames are listed just by model number, but others are really simple and listed by C10, K20, Burb, etc. I think those ones were handed to salesmen at the dealership.

 

[HotRodPC]

I've seen scans of different charts posted before on the internet, but I haven't had any luck finding them again. Some of the charts are hard to read because the frames are listed just by model number, but others are really simple and listed by C10, K20, Burb, etc. I think those ones were handed to salesmen at the dealership.

I know I've heard mixed answers between C10-C20 and K10-K20. I've heard, no difference, C20 is 1/16 thicker than C10, but K10 and K20 are the same, and I've heard C20 and K20 are 1/32 thicker than C10 and K10. On the one that says C20 is 1/16 thicker, that C30 is also the same but the frame rails are taller. I did know C30 rails are taller, not sure if K30 are but I'd imagine so.

 

[bucket]

I know I've heard mixed answers between C10-C20 and K10-K20. I've heard, no difference, C20 is 1/16 thicker than C10, but K10 and K20 are the same, and I've heard C20 and K20 are 1/32 thicker than C10 and K10. On the one that says C20 is 1/16 thicker, that C30 is also the same but the frame rails are taller. I did know C30 rails are taller, not sure if K30 are but I'd imagine so.

There's oodles of confusion on the subject because the specs changed through the years. Plus there were variances when the rails were stamped so some sections may be a little thinner than others. Not to mention guys trying to measure the thickness of their rusty, scaly frames.

Really though, the differences are minor and it probably doesn't matter anyway. Oh, yeah the K30 frames are taller like the C30.

 

[GreaseDog]

K10 had 10 bolt rear, K20 had 14 bolt full-floater. Up front not much difference in axles, other than K20 had 8-lug outers and a little bigger brakes. Otherwise, same ole 10-bolt front axle. Some K20s probably have beefier leaf springs all around, and the rears are 56" instead of K10's 52" Hope this helps!

73-76 would have a dana 44 front, 77-80 could be a dana 44 front or a 10 bolt, after 80 everything got a 10 bolt front.

Half ton rears from 73-81 were 12 bolts, 82+ were 10 bolts.

3/4 rears from 73-80 were all 14ff, after 81 could be a 14ff or a 14sf.