Red arrows or blue arrows? But in either case I see nothing to worry about...

 

There is a gap where the red arrows are.. Because the crosmember does not fit the frame rails I am woried that the crossmemeber wil eventually crack again because of metal fatique.. I think that is what happened with the previous one.

 

Those things were not all that precise in the first place so just torque the bolts down well and it should pull into place..what you have is a common issue..

Sam

 

All the bolts are allready torqued down. The back of the crossmember just isn't flat so the gap remains.. Won't this cause problems?

 

If you are that concerned then you can heat the crossmember with a rosebud torch until it is good and red and then torque the bolts to pull it flat..Since 1964 something may have warped or twisted to show that kind of issue..Not to worry too much as those trucks are plenty strong..

Sam

 

When changeing my 66 to a 72 front crossmember to gain power sterring and disc brakes and 5 lug wheels i had the same gaps ,i installed U shaped alignment shims so bolts would torque properly and had to drill 2 holes 7/16 from the original size the 72 holes all align but 2 are larger i dont know why ,this a good swap IF you want p/s disc brakes its almost a direct bolt in -your replacement could be 67-70 would still have 6 lug wheels but different bolt sizes also i really cant see that good but the head markings on your bults don seem to be grade 8 VERY IMPORTANT

 

Do you have some pictures of your solution?

Today I discovered that my crossmember is also cracked in the front lower corner....

Is there a good solution for strengthening the crossmember? My previous one wa also cracked in both corners.

 

What cross-member did you use?

I used one out of a 1976 C10 (Started out with a bad 1981 crossmember, then discovered that 73-80 use SAE flare fittings on PS box), which seemed to fit almost perfectly.

I am aware of the fact that the overall "track" (spindle to spindle) width will be about an inch wider than the original, and hoping this won't matter.

My Jounal Page 12

Edit:
Yup, those are cad-plated Grade 8 bolts and nuts.

 

Thank you for the pictures.

I am using a crossmember of a 67 c10. I have a new spindle and disc brake set for the original control arms.

A younger front clip would have been a better solution but now I have allready spend quite a bit of money on this one..

I can weld the crack on my crossmember but I wonder if there is a good way to make it stronger to prevend cracking in the future...

 

I would install braces on the inside ... like I have.
Those were factory peices off of the 1976 C10 as well, but they could be duplicated using angle-iron?

I don't know how much of my journal you have read, but the first crossmember that I had cleaned up was one out of a 1981 C10, and several alignment shims (maxed out, actually) had been used.

When I spotted the 1976 clip with the braces ... my thought was that anything that stiffened that area would help with the big-block.

 

I have read your journal. I saw that the braces only support the lower 2 bolts on the side. (The pictures are very helpfull)

Will this braces prevent the crossmember to crack?. In this picture I located where it has cracked.

 

That seems to be an odd place to crack to me, as you would expect the weight would be trying to compress, rather than stretch, the metal there.

But yes, I suppose the braces on the inside of the frame would, as I said earlier, fortify and strengthen that general area. In order to stretch the metal on that side, it would have to "compress" the metal in the brace. The brace, in effect, is basically doubling the thickness of the frame.

Edit: I suppose that you could also weld on another layer of steel plate on the outside edge of the bracket to reinforce it?