C series suspension/engine crossmember questions
 

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.

Re: C series suspension/engine crossmember questions
 

Upper a-arm studs are larger on C20's/30's.
73-87 x-members might require a couple of holes to be opened up/re-drilled when used on pre 73 chassis.
Motor mount stands can/do vary in height between 6x-72's & 73-87's.
Brake line mounting tabs are in different locations.