Anyone know what these sensors are?

What are these two rusty sensors??..where do i hook em up? Almost ready to swap in the 350 but i need to know what these are so i can replace them beforehand.

http://i50.tinypic.com/wvsk08.jpg

Larger one: Oil pressure gauge sender.

Smaller one: Oil pressure switch for idiot light.

Unless the car is TBI or has an electric fuel pump for some reason (not likely on an '83). If it were TBI the switch would also be the auxiliary fuel pump power switch.

Larger one: Oil pressure gauge sender.

Smaller one: Oil pressure switch for idiot light.

Unless the car is TBI or has an electric fuel pump for some reason (not likely on an '83). If it were TBI the switch would also be the auxiliary fuel pump power switch.

Thanks!