My bracket for a saginaw pump came with my old 400 block that was cracked. I’m mocking it up on my good 400 block, also late 70s casting. It has five holes- two go to the water pump housing (1 with a built in standoff to even the heights) and one goes to a threaded boss on the front of the block below the head.

That leaves two holes that are actually tubes to mount the moving pump body and brackets that bolt to the pump. The upper one is shorter and holds the pivot for the pump. It has a captured nut on the rear pump bracket.

The bottom tube is longer and lines up well with the bolt that should tighten down in the adjuster slot as the pump swings in and out. The problem is that it goes all the way back to almost touching the block and there are no threads, no tapped hole there, or captured nut. There is not even room for a nut or a bolt head behind there.

Am I missing a boss that is on some blocks? My instinct is to cut the bottom tube shorter and tack weld a nut on there but not if there is an easier way that ma mopar did it?

Here’s a disassembly pic. Sorry for the link- still haven’t figured out how to post pics here. In the pic you can see all the mounting bolts I DO have- the one bolt that’s slightly loose/slid out on the bottom is the one I wish I had a better pic of!