Im my eyes that block is JUNK! i would NOT grind it off to see what's there, i would beat the h e double tooth picks out of it unit it broke... one way or another......then to the scrap heap it would go.
It runs, it don't leak! beat on it until it blows.
Yes there are people that can fix cast iron...and make it last??????? But no one close in my area.
I would beat on it until it Blows! have zero dollar into the motor and would not spend one dollar on it.(ok, it need a intake gasket set to make it run again). it don't even deserve a fresh carb or intake.
Now that i have said all of that......would probably pull the motor, reinstall the intake and then tape up all the ports to protect the crank, rods, heads and intake.
Then junk the block when them parts are used up................
