K20 k30 frame differences?

[Rmauto1]

Hello everyone! I have a 1978 k20 with a kinked frame. I was wondering if any one here knows if a k30 frame is any more heavy duty than the k20 frame. I have heard that the k30 frames have taller rails in certain areas( under the rear of cab, and front of box.) I am going to change the frame anyway, is it worth trying to find a true k30 srw frame for it?

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[guitarfreak235]

sorry cant help with the frame stuff. But nice truck! reminds me of the k20 at the fire department i pass everyday.

 

[Rmauto1]

Thanks bud! Yea it's a really clean truck. 15,000 original miles. I bought it about 5 years ago for 1600.00 with a hole in the original 400. I put a big block in it, and the step side box. Should be a really nice truck when it's finally finished! Basically building it to look like it should have looked stock. 4inch lift, stock steel wheels, Dana 60 and 14 bolt with the big rear brakes out of a crew can. I put the long step on it just because it was originally a cab and chassis, and I never see long step side trucks here. I am going to look at a 1 ton srw frame on Sunday, I'll take some measurements before I go.

 

[Stroked]

Supposedly the K30 frame has thicker rails than the K20. I believe the K20 frame is the same as the K10 frame.

 

[Rmauto1]

That's what I've always heard. I found the frame dimension prints in one of the other threads here, but they are too small to see on my phone. I guess I'm gonna have to find a desktop unit to read them.

 

[HotRodPC]

There is not alot of difference in a 1/2 and 3/4 ton frame. But there is a huge difference in a 3/4 and 1 ton frame. Made of the same carbon steel material, but the 1 ton frame rails are also taller. The thickness might be the same, but the rails are obviously different.

 

[Rmauto1]

There is not alot of difference in a 1/2 and 3/4 ton frame. But there is a huge difference in a 3/4 and 1 ton frame. Made of the same carbon steel material, but the 1 ton frame rails are also taller. The thickness might be the same, but the rails are obviously different.

Thanks a bunch for the advice hotrod pc!! I think I found a good clean one, gonna go check it out on Sunday. 500 seem like a fair price for a good clean k30 frame? I've seen a bunch of 3/4 ton frames that were pretty rough, in the 300 range.
Anyway, thanks again!

Randy-

 

[HotRodPC]

If that's what you really want is a K30 frame, and it's a good clean one, $500 probably isn't to bad. You don't find those for sale often. Not sure what your intent is with the truck, but some claim the 1/2 and 3/4 ton frames are better for wheeling. The 1 ton frames are more rigid and don't flex as much, so you can get into situations where articulation might be necessary, and a 1 ton might leave a wheel up in the air where the 1/2 or 3/4 ton might have allowed all 4 wheels on the ground. Of course many things can be done with suspension to compensate for articulation. Also, because of the taller frame, the 1 ton crossmember is different. So if you go get this frame, I'd try to make sure the cross member is included or you might have a hard time finding one and have to make your own.

 

[Rmauto1]

It is. The original plan was to use the truck as a stock class puller, I've kinda gotten away from that plan a bit, but I still want the heavy frame. From all the pics I saw of it, it looks like all the cross members are still there. Thanks again for all the great input!!

 

[bucket]

The K30 frame uses different rear spring hangers and shock mounts. You will have to swap that stuff or move the perches and shock mounts on your axle. Or use a K30 axle too.

 

[Rmauto1]

The K30 frame uses different rear spring hangers and shock mounts. You will have to swap that stuff or move the perches and shock mounts on your axle. Or use a K30 axle too.

Thank you⬆⬆⬆