[Lynn]

Small block shroud is attached at the bottom with nothing more than clips that are part of the radiator.
They are often missing, so guys improvise. Apparently someone improvised on yours. I hate to assume, but it sounds like someone riveted it to the bottom brace on the core. Do the rivets go straight up from the bottom?

The rivets are not factory. Be carefull drilling. Go through to far and you could punch a hole in a tube.

I would grind off the heads first, just to get the shroud off.

Fan clutch is a slip fit onto the water pump shaft. Just remove the four nuts (or bolts if the studs have been removed.... often see bolts in place of the studs and nuts) and it should come right off. If it is stuck, soak it in some penetrating oil, then tap lightly.

Good luck.