Newb Frame/Suspension question c30 GMC

[jdionne]

I have a 72 GMC 1 ton, non-dually. The front cross-member, the piece the lower a-arms connect to and that the front springs sit "in", is rotted on both sides where the top of the coil springs rest. The drivers side isn't too bad but on the passenger side the top is rusted so bad that the truck is sitting lower by a couple inches.

2 questions :

1. Is this piece specific to the C30's or would a 3/4 ton piece fit (my guess is the half ton would not be the same)
2. Is this piece welded or bolted on, or both, if I could find a piece to replace is replacing it a gigantic task?

Thanks in advance!