72 K20 Crossmember question

[Yammerhammer]

Hello, Im a long time lurker but I dont post much. We picked up a 72K20 for me son and I to build for his first truck. What little history I know is that it was a factory auto a/c p/b p/s truck. The guy we had gotten it from to the cab, clip and bed off and cleaned, re-sprayed the chassis and put it back on with 2" body lift. He didn't connect anything back up except the steering column. He had set a 292/SM465 in, for what reason I dont know however, the 6 banger was not bolted, didnt line up with crossmember. Now my son and I plan to keep the SM465 but put in a big block. As I took out the 6banger, I realized the holes in the crossmember dont line up with the ones in the frame. The frame has three holes, each side, top and bottom. The crossmember has two holes, each, top and bottom. These two holes dont line up with any two of the three on the frame. Wrong crossmember or????

[CUSTOM/10]

We need to see some more pictures of the frame and the crossmember. But from what I can see I think you have a 2wd frame that was being converted to a 4wd. Can you get some pictures of the rear of the frame where the axle mounts and how the springs mount, and some over all pictures of the frame. If I'm correct this would explain why the engine crossmember doesn't line up with any of the holes.

Gary

[Yammerhammer]

I can get some this evening...

I thought the same about 2wd but the front spring mounts are factory riveted, not bolted.

[CUSTOM/10]

Get a bunch of pics and that will help.

The 2 large round holes in the side of the frame rail are what I'm questioning.
I don't think 4wd frames have those !

[Yammerhammer]

I believe you are correct after you pointed that out, TY! I'll just re-drill new holes and plug weld all the old 2wd ones.

[CUSTOM/10]

What about the rear of the frame, does it bow out to the sides above the rear axle, if so it's a 2wd frame, if the rails are straight it's a 4x4. The pic below is a 2wd.

[Stocker]

My '72 K20 has 2 holes for the crossmember, and does not have the 2 large holes in the side of the rail.

[57taskforce]

My K/20 doesn't have the holes in the side of the frame either

[BLAZERMAN]

Crossmember is for a 67-72 V-8 but I think the previous owner used a 73 up chassis.

[57taskforce]

Originally Posted by BLAZERMAN

Crossmember is for a 67-72 V-8 but I think the previous owner used a 73 up chassis.

Good eye, 2" body lift could be a clue here.

[Yammerhammer]

I didn't get a chance to look at frame last night but here is what I do know. The cab was originally a 72 C20 auto. It's been converted to SM465, hence the body lift to clear the hump. It has drum brakes all the way around and all springs, spring mounts are riveted to the frame. It doesn't seem as if any of the body lift or body mounts have been altered and I'm sure the 67-72 mount different than the 73-up. I'll get pics tonight however, at this point, I'm going with original c-20 frame thats been converted to 4X4. Good thing I only have $650 in it to this point.

This was after we started to take it apart but you get the idea...

[Stocker]

Originally Posted by Yammerhammer

It has drum brakes all the way around

That would indicate a frame no newer than 1970, as front discs were standard beginning in 1971.

[57taskforce]

Originally Posted by Yammerhammer

I didn't get a chance to look at frame last night but here is what I do know. The cab was originally a 72 C20 auto. It's been converted to SM465, hence the body lift to clear the hump. It has drum brakes all the way around and all springs, spring mounts are riveted to the frame. It doesn't seem as if any of the body lift or body mounts have been altered and I'm sure the 67-72 mount different than the 73-up. I'll get pics tonight however, at this point, I'm going with original c-20 frame thats been converted to 4X4. Good thing I only have $650 in it to this point.

This was after we started to take it apart but you get the idea...

If the front spring mounts are riveted it's probably not a converted c/20 frame. Just because it has drums all the way around doesn't rule out the possibility that someone swapped an older front axle under it. Pics of the front frame horns where the bumper bolts up might help identify It if they aren't cut up. The gap between the bed and the cab looks long to me which could be the result of a 73-87 frame but then again it could be the angle of the pics. Regardless of what it ends up being it looks like a great starting point.

[BILT4ME]

Look on the top of the frame rail right where the steering gear is located and see if there is a VIN number there. List that number on this forum and these folks can interpret it for you. Then you'll know what the frame is. Compare this number to the VIN number on the cab.