Shaving F-150 bedrails

Hey, can stainless be welded to regular steel? The only caps I can find are stainless. The truck is the 04-07 with the real short box. If it can be welded, is there a special gas required or ??? Thanks in advance.

no the stainless caps are gonna be tooo big, y dont u just shave each hole, or cut it all out and weld in a piece of steel?