Wrong sway bar

Looks like a 67-72 type K-member since I don't see a hole through that a 73-76 style K-member would pass through it.

Like junkyardhero said, you have slider calipers (73'-76') style and they are mounted on the front side of the spindle. To move them to the rear for sway bar clearance, you swap the spindle from side to side and mounting the calipers so the bleeder screws are on top. Then you'll need different caliper hoses. Dr.Diff sells some.

It also looks like someone did a 3" rear spring relocation on your A-body since the rear shackle hole goes through the frame.

Yes that oil pan is lousy for a street driven car unless you jack the front end way up.

You've bought yourself a modified car. Lots of learning to do on what was done to it. Not for the faint of heart.