2nd Gen SN pylon support?

Before I throw the 440 back into the 73 and try running it on the hose, I wanted to address what were obvious issues with the pylon. The pylon looks rotated about 30°, it has a lot of play, and the floor felt pretty soft. I felt underneath the floor and it was clear that someone has tried to reinforce it at some point, but did a very poor job.

I pulled up the carpet around the pylon and noticed an aluminum flange that bolts through the floor and was welded to the pylon. I don't know if this is even the right flange, or if it is supposed to be welded or not, but whoever welded it didn't make sure the alignment was right. So the square flange is about 30° off of the ring/finger. Looks ridiculous. I grabbed the Sawzall and went to work cutting out the whole area between the primary stringers. I discovered a pine 2x6, some unsaturated glass, and believe it or not, some 1/2" OSB all sandwiched under there and held together with about 6 wood screws. It was pretty damp but even when it was dry/solid wood this wouldn't have (and didn't) hold up.

The cup that is glassed to the hull seems okay. Then there is this offset piece that inserts into the cup and moves the mounting point for the pylon about 4-5" forward. The pylon was then inserted into there. No clue if any of this is original, but I assume it is because the motorbox wouldn't be able to close if the pylon wasn't moved that far forward. I just don't know why the cup that is glassed to the hull wasn't positioned forward enough to where you don't need the "offset" piece in there.

I need some guidance on how to repair this. My plan was to CPES the primaries and exposed edges of the floor, then bed down a piece of 3/4" ply that has another piece of 3/4" ply sandwiched to the bottom. Don't know if that's enough support, or what the factory might of had originally.

Before anyone suggests it, I will say that I'm fully aware the stringers are probably soaking wet and if I'm going to tear into this at all then I should consider a full stringer job. However, I won't be doing that, at least not yet. I plan to fix this pylon issue, get the engine back in it, and go skiing. Maybe down the road when the 67 project is done I might consider tearing into this one more.

Pics would be great. I am having trouble visualizing what you have for a hull mount. Sounds like the cup is in the "normal" spot (for a typical small block boat) and someone came up with a way to compensate for it (big block extending further forward).

If that's the case, I would strongly consider grinding the cup out of the bilge and relocating it to the proper spot. Heck, I might have a cup somewhere if you just want to add a 2nd one and leave the original in place.

The only thing keeping the early pylons (pre 76) indexed properly was the small bolt through the pin/cup at the hull. The welded square flange that through bolted (with backing plate) at the floor came later. 73 would have just had a beauty ring at the floor. There wouldn't have been any other metal reinforcement at this point, just a (thick) wood crossmember covered in glass/gel.

Apparently a few of us are following your project ..