the 8.1 came with stainless elbows. so you dont have to worry about the elbows BARR probably made the castings for Mercruiser as they are one of the OEM casting houses for Merc, Volvo, PCM, Indmar, and Ilmor.
Bittersweet..... Lost my good friend Jeff to cancer a few weeks ago. His widow offered some boat stuff.
Two ditch bags, wet suit, air horns, Bennett repair kits, dock lines, ski ropes, dock step, spare anchor, small fuel tank
after adding my first oil drain kit, that is what I do now for all marine motors. yes, the oil has to be warm. and yes, it takes about a beer or two's worth of time to drain via gravity. however that is when I change the fuel filters and oil filters.
remember, these motors area a derivative of the industrial motors and came down the same assembly line as the truck motors. other than core plugs, head gaskets, cam and the circulation pump. it is essentially a truck motor.
some of the marine motors used the larger industrial engine oil pan...
First, welcome aboard
Members come and go
Restorations all take the same path. De-rig the boat, build a cradle, uncap the hull, cut out the bad, replace with good. Re-rig
Looks like the hull structure is rotting and the boat needs the hull to be restored.
Could be poor layup, however my guess is the foam is waterlogged and the stringer grid needs some attention
Should pull the drive every year to check alignment, u-joints and gimbal bearing as part of the winterization process.
Read this. https://forums.iboats.com/threads/winterizing-inboard-and-i-o.770207/
The numbers are all in a tight window, that is good.
Your gauge is either reading 30 psi high or you have water or oil in the bores
Where did you source the carb?
The wiring on the starter needs some love. The crimps are sub-par and the terminals need cleaning
ABYC color codes listed in the electrical forum stickies.
Motor wiring is about the only documented schematics
AD posted the wiring diagram for your motor