1966Oldsmobile

Hello, I´m rebuilding a 66´ 330 Olds engine and forgot some important details. Hope someone can help me.
1. What hose is this and where does it goes
2. What to mount in that hole
3. Where to mount the grinding

please see numbers on the pictures. Thank you very much. I should have taken more photos :-)

nsnarsk65cutlass

#1 heater hose #2 temp sender #3 ground wire to back of rh(other cylinder head) to firewall.

1966Oldsmobile

Thank you very much!