That bracket is for 348 or 409 motors only with power steering - it’s one of two brackets that mount to the engine block for 409 power steering.
In your first picture the bracket only mounts one way. Turn the bracket to the right with the slot turned toward the frame rail. The slot allows stud on the back of the PS pump to be adjusted for tightening the belt.
The small hole mounts to the front exhaust manifold bolt with a Allen head bolt with double thin nuts( your kit does not have this Allen head bolt( why ?? It doesn’t have this bolt is wrong). I looked at the picture of the kit on Ecklers). The hole in the bracket with the round ribbed edge on the bracket mounts to the front of the head.
In order to mount the bracket to get it to align correctly the front exhaust manifold bolt has to have one nut to hold the manifold and one to hold the bracket. My experience is that a regular bolt holding the manifold and the bracket will not work....uu
Pictures of what I am describing attached
Paul