Most 350's operate in the 190 to 210 degree range so the hoses need to be able to withstand at least those temps.
According to the book it should be #12.
Chevy Cavalier should run about 195F or 91C
how to instill a deluxe heater in a 55 chevy
The block heater cord is on the Engine Block Heater on the 2007 Chevy Optra.
How do i cange the heater core of a Chevy s 10How do i cange the heater core of a Chevy s 10
how do i change a heater core on a 2000 Chevy impalla
heater sensor circuit Chevy astro 2000
How do i remove a heater core to a 1974 chevy impala?
how to replace a heater core in a 1997 Chevy blazer
Take out the whole dash and then the heater core should be behind the glove box on the passenger side.
The heater core itself, should be under $50. Installation aprox $300 to $400.
follow the upper radiator hose, that should lead you to it.