Here’s the f-body alternator mount. See how it glistens. If you read the forum post you’ll see that the boss for the bolt is on the truck engine but it needs drilled out. Public service announcement: don’t be a ramjet like yours truly–this hole needs to be straight and it needs to be in the center of where the alternator mount lands. I marked the spot less carefully then I should have, then, lacking a punch, attempted to just drill it. Not recommended. Use a punch, punch the center, use a sharp bit, do not be me. Can’t stress that enough. The drill bit walked just a little bit, but it was just a little bit too much. I got my engine all put together but I had to ream out the holes through the mount and through the alternator to get the bolts started.
If you go this route you’ll see that the bracket actually has three mounting points but the block only has locations for two spots. My original plan was to weld a nut onto the block. Once I saw how bad I screwed up the rest of this mounting bracket I decided that if two mounting points was enough for the rest of the internet it would be enough for me too. I have about 200 miles on the mount so far and a significant portion of that 200 miles is at 4000+ rpm. It has held at 6200rpm with no apparent problems so far.