C series suspension/engine crossmember questions

[flatbed82]

I'm trying to find out what C series front suspension/engine crossmembers will interchange, all I'm wanting to know about is the crossmember none of the suspension components. Are they the same from a c10, c20, or c30?

I maybe swapping a 69 c10 over to disc brakes and I have everything from the controls arms out from a 78 c10 that is in good shape. Just trying to find out what crossmembers from 73-87 are the same or what I need to look for when I go to buy one. I used the 78 crossmember I had replacing the rusted one in my 86 GMC.