Crossmember Swap

[6D8_C10]

Hey guys, I possible have a good deal on a crossmember swap.

There is a guy on CL who is selling his crossmember from his '71 disc brake truck for $100.

My question is, will this be a good swap for my '68 to convert to 5 lug disc or should I wait and look for a 73-87 crossmember?

What are the pros and cons for the 71-72 crossmember vs. the 73-87?

Oh, my plan is to put drop spindles, springs and rebuild what is needed before dropping my crossmember.

[Fitz]

Why change it at all? When I went to Discs on my 67 stepside I pulled off all of the front suspension pieces, leaving the crossmember undisturbed. I bought 2 1/2 in drop spindles and 2 in drop springs from Early Classic Enterprises and rotors and calipers from Classic industries. Powder coated all of the steering parts including upper and lower A arms, springs, spindles etc and reassembled everything. Didn't touch the crossmember at all!

[6D8_C10]

Originally Posted by Fitz

Why change it at all? When I went to Discs on my 67 stepside I pulled off all of the front suspension pieces, leaving the crossmember undisturbed. I bought 2 1/2 in drop spindles and 2 in drop springs from Early Classic Enterprises and rotors and calipers from Classic industries. Powder coated all of the steering parts including upper and lower A arms, springs, spindles etc and reassembled everything. Didn't touch the crossmember at all!

Are your new spindles for 71-72 or are they the 73-87?

My thinking is that I could get the crossmember sand it, painted, upgrade whatever while I drive my truck, then when it is ready, just swap it out.

But, part of my question is, do I get that crossmember or do the 73-87 swap?

BTW, your setup look pretty good.

[PanelDeland]

Parts for the 73-87 are a bit cheaper.I would look at the price to rebuild each and go from there.

[fleetimus]

Another advantage is, the 73 and up has rubber A-arm bushings. A little smoother ride. I put a 75 in my 68. Like you stated, everything rebuilt and painted. Unbolt and bolt.

[68C15]

I put the whole works from an 80 C10 under my 68. keep in mind the 73-87's have 1/2" bolts for the X member mounting while the 67-72 have 7/16". just take a 1/2" drill to your frame while it's out.

[gkesseru]

I'm just about to do this swap putting an 81 entire front end into a 68 C10. I just found out that the 81 measures a 1/4" wider at the frame at this point than the 68. It looks like I may have to grind off the rivets of the front cross piece so that the frame may spread this 1/4". Or can I just force it? Another difference that I noticed is that the 68 frame is 1/2" taller (5 1/2" inside vs. 5" for the 81). As a result, I may have to use the 81 motor mounts but bolt the mount-perch inside the C frame inside of above it as in the 81.
Anyone else done this?

[boogie67]

I don't know if the 81 and 82 are different.I put an 82 under my 67 and it went in perfect.The only thing I had to do was drill one of the holes on each side .

[tonypaul]

Originally Posted by gkesseru

I'm just about to do this swap putting an 81 entire front end into a 68 C10. I just found out that the 81 measures a 1/4" wider at the frame at this point than the 68. It looks like I may have to grind off the rivets of the front cross piece so that the frame may spread this 1/4". Or can I just force it? Another difference that I noticed is that the 68 frame is 1/2" taller (5 1/2" inside vs. 5" for the 81). As a result, I may have to use the 81 motor mounts but bolt the mount-perch inside the C frame inside of above it as in the 81.
Anyone else done this?

How did you find out? Did you measure it or someone tell you? I have a 1980 5/8's ton (heavy half) and everything lined up perfectly, other than having to enlarge a few of the bolt holes in the frame. Just geussing but if your going off a measurerment, maybe the frame has had some damage and be off. But whatever it is I hope ut works out for you....

[6D8_C10]

Originally Posted by gkesseru

I'm just about to do this swap putting an 81 entire front end into a 68 C10. I just found out that the 81 measures a 1/4" wider at the frame at this point than the 68. It looks like I may have to grind off the rivets of the front cross piece so that the frame may spread this 1/4". Or can I just force it? Another difference that I noticed is that the 68 frame is 1/2" taller (5 1/2" inside vs. 5" for the 81). As a result, I may have to use the 81 motor mounts but bolt the mount-perch inside the C frame inside of above it as in the 81.
Anyone else done this?

Hey gkesseru, I am with tonypaul. every post I ever read, said that the frames match up. 1/4" sounds like it is just off or bent.
As far as being 1/2 taller, I hadn't heard anyone having problems with it.
Good luck

[LockDoc]

-
I've done the complete crossmember swap on a '70 Chev and a '70 GMC with no problems except having to re-drill one hole and enlarging another. Some of the later ones have stiffeners inside the frame rails and I would recommend using them. If you are having problems with different widths then I would say that one of the components has been damaged at some point in time, either the frame or the crossmember....

LockDoc

[gkesseru]

I have a 68 rolling frame less engine right next to the 81 rolling frame less engine. I measured from identical points on each frame. My problem might be that I'm too much of an A personality and actually measured first. Once I unbolt I'll probably find out that they bolt right up without any forcing. All of your responses say that this should be easy.
I don't see any evidence of a repaired or bent frame on either one.

[jr3381]

I have a 1972 gmc half ton short bed. I have stripped it down to bare frame leaving the front crossmember attached. I have already purchased all of the front end components; drop coil springs inner outer tie rod ends upper lower balljoints etc. then I realized that my front cross member has a few tender spots and am under the impression that the 73-87 cross member will fit? if I do this swap will all of those parts still fit or would I have to buy different?

[Tx Firefighter]

Originally Posted by jr3381

I have a 1972 gmc half ton short bed. I have stripped it down to bare frame leaving the front crossmember attached. I have already purchased all of the front end components; drop coil springs inner outer tie rod ends upper lower balljoints etc. then I realized that my front cross member has a few tender spots and am under the impression that the 73-87 cross member will fit? if I do this swap will all of those parts still fit or would I have to buy different?

Yes, it will bolt right to your frame. Then rebuild your 72 model suspension pieces with your new parts and bolt them to the crossmember.

The only real difference is your 72 model crossmember has brake line tabs on the front edge of it that the 73-87 don't. You'll have to figure out a way to secure your metal brake lines afterward.

[jr3381]

So all of my parts will fit? I also need the brackets at the top of the cross member that the upper control arms bolt to. Where could I get those if I just end up repairing my current cross member. I can't find those brackets anywhere on the internet.

[Tx Firefighter]

Originally Posted by jr3381

So all of my parts will fit? I also need the brackets at the top of the cross member that the upper control arms bolt to. Where could I get those if I just end up repairing my current cross member. I can't find those brackets anywhere on the internet.

They're very solidly riveted to the crossmember. In other words, you'll get them when you swap crossmembers.

This is a picture of one a little bit older, but as you can see, it's all one deal, crossmember and upper arm mounts.

[jr3381]

I already have the arms and everything off the only thing connected to the frame is the member itself. I believe I can grind down and drill out the rivets and replace the brackets if I could find some. Or I may be able to make my own brackets? reason being I think I can repair my xmember and don't want to buy one if I don't have to lol

[Tx Firefighter]

Whichever works best for you.

[gkesseru]

TO get my newer crossmember, I bought a non-running 81 C-10 for $500. Parted out the cab for 200, bed for 400, took off crossmember and wheels and took rest to recycler for 6 cents a pound.
BTW, the best way to find out what fits is to go online to Autozone, Advance, or Rock Auto and look up part number for donor frame and compare to part number for your older frame. I usually do this on Rock Auto.