Is this a common problem?

[bucket]

i think the trailing arm on my c20 is coming apart. there is a plate on the bottom of each arm. looks to be spot welded in place. one of them is actually peeling off from the front. are these plates factory or have they been added? i'm thinking about just plug welding back into place with my MIG.

Also,

I have a part-time landscaping buisness and this beast is my mule. last weekend had her loaded down with sod and a 12' utility trailer w/ trees. the back end sagged so far that the panhard? mount on the axle crushed my new exhaust that exits behind the rear wheel. i'm probably should replace the 35 year old springs. anyone have suggestions on heavy duty springs or ways the exhaust should be routed over the axle?