The factory hose run for the raw water intake on the O-34, has the sea cock under the galley sink. Then the hose went thru a drilled hole in the end part of the nearest hat stringer, under the teak/hollly sole section, and then under the starb. side of the engine compartment face. They routed it into the engine bay thru a drilled hole in the bed log inside face, forward part near the RW pump on the engine.
I long ago re-routed the intake back under the aft berth and added a Groco strainer -- the routing from there up the starb. side of the engine is shorter with few turns.
Now, back to the question... I have poked a finger into that hole in the frp bed log, and my best guess is that the wood inside is (duh) laid up against the top where the mount lag-bolts/screws are torqued down into it. What with the thickness of the frp section and the added wood, the large screws hold well. Still, as noted, they will loosen up over time. Lots of vibration in a small diesel, is my surmise.
Referring the pix in my engine-changeout blog on this site, the new aluminum riser bars were secured with "machine threaded" bolts into new holes in the fiberglass and into what, from inspection of the sawdust, was oak. (Our engine installer complimented EY on using good material.)
Back to the present and the need to get new lags to hold, my best guess is that the old hole will need to be expanded and filled with thickened epoxy and then threaded for a bolt. Easy to do with the engine move out of the way, but... oh my. More work. Having moved our old Universal out onto the cabin sole, it is quite a bit of work (at least for an amateur like me).
**DO... place a fitted piece of 'masonite' over that sole section before putting tools and dunnage and possibly an engine on it. I did, and the expensive sole section was unharmed.
Not trying be a sunshiny Pollyanna kind of person, but having most sailing/cruising shut down or limited for this summer, does provide an opportunity for a lot us to complete long-contemplated boat projects and upgrades. FWIW, restoring the soundproofing and all of the hose and wiring inside the engine compartment was
Hugely Rewarding for me. The Admiral was noticeably impressed-- she likes
tidy and reliable things on the boat.
Keep those pix and narratives coming. As Red Greeen used to say on his marvelous show: "Keep you stick on the ice, and we're all pulling for ya."