Replace rear shock crossmember?

[crakarjax]

I'm installing c-notches right now and removed the shock crossmember to make it easier to work in the area. I'm debating whether to use it (it's in great condition) or install something tubular. I'm moving the shocks so I don't care about mounting them to this crossmember, but I'm also mounting bags to the frame and the bag fittings will be run through a hole in the frame, so clearance for that is a concern.

• How do tubular crossmembers compare in rigidity to the stock crossmember?
• I've seen universal tubular crossmembers (trim to find and weld-on ends) -- has anyone placed these in a non-stock location and is there any benefit to doing so?
• Any specific product recommendations?

[crakarjax]

Any thoughts? As I've researched this, I see people (including Hotchkis) adding gussets to the top of the stock shock crossmember. I'm kinda leaning toward reinstalling it now since the c-notch doesn't want to line up quite right without the added thickness below the frame, but since I have the C-20 frame stiffeners I'll need longer bolts to do the install and am still not sure how the airbag install would turn out.

[Ironangel]

If the air bag kit was designed for 67-72 frames, the stock crossmember shouldnt be in the way of anything...

[crakarjax]

Originally Posted by Ironangel

If the air bag kit was designed for 67-72 frames, the stock crossmember shouldnt be in the way of anything...

It's not a kit, just some bags and 90* fittings... I'm not using upper cups like I've seen elsewhere, so the fitting will be poking through the frame and x-member support.

[Ironangel]

Originally Posted by crakarjax

It's not a kit, just some bags and 90* fittings... I'm not using upper cups like I've seen elsewhere, so the fitting will be poking through the frame and x-member support.

I see...If your relocating your shocks then a tubular aftermarket or modified stock crossmember should be ok as long as a gusset is used to support the tube connection from the either upper or lower (depending where you locate the tube x-member) "C" portion of the frame rail. Most c-notched trucks will never see loads and frame twisting stresses that constitute full blown frame rail integrity...

[Andy4639]

Originally Posted by crakarjax

Any thoughts? As I've researched this, I see people (including Hotchkis) adding gussets to the top of the stock shock crossmember. I'm kinda leaning toward reinstalling it now since the c-notch doesn't want to line up quite right without the added thickness below the frame, but since I have the C-20 frame stiffeners I'll need longer bolts to do the install and am still not sure how the airbag install would turn out.

Look at the 'NO LIMIT" shock relocator kit. It is a nice kit and helps with rear body roll as well since they are mounted outside the frame rails. A good fab person could easly do this them selves. The link is to the kit.

http://67-72chevytrucks.com/vboard/s...d.php?t=477839

[crakarjax]

Originally Posted by Andy4639

Look at the 'NO LIMIT" shock relocator kit. It is a nice kit and helps with rear body roll as well since they are mounted outside the frame rails. A good fab person could easly do this them selves. The link is to the kit.

http://67-72chevytrucks.com/vboard/s...d.php?t=477839

I am planning to relocate my shocks, I'm just going to mount them on the frame rails. I really just need to figure out what to do with the shock crossmember since I don't have shocks mounted to it anymore.

Anyone know the stiffness of the stock x-member vs a tubular replacement by chance?

[Andy4639]

Just leave it off. all it is is a mounting bracket for the shocks it doesn't add anything to the frame.

[crakarjax]

Originally Posted by Andy4639

Just leave it off. all it is is a mounting bracket for the shocks it doesn't add anything to the frame.

Well I'm sure it adds some stiffness, and I've seen others use it to tie in cross bracing -- I'll attach some pics if I can find them.

attached

Now, I'm thinking maybe I can chuck that crossmember and use a welder series sway bar as pictured, but going through the frame while adding some boxing in the area as well. Then I can also tie in some diagonal tubing between the sway bar outer tube and the frame, similar to the pictured cross-bracing.


You can see more details in the guy's build thread here
http://67-72chevytrucks.com/vboard/s...d.php?t=534956

But his panhard bar placement is suspect so I'm not sure if the placement of his bracing is optimal.