I'm just guessing but i think its 4, that would be the obvious answer. but i really have no idea
no
Heater core will come out under the dash on the passenger side. it is possible to change the core without removing the heater housing. there was two different size cores as I remember but both will fit.
I have a 1970 F100 and it has two lap belts that look original. I don't know if it ever had one in the middle, but I doubt it.
Check your alternator belts. Might be slipping or broke.
come on! blue falcon!
Seat belts, yes.
a wool fabric
No, the 1957 Chevy didn't come with seat belts.
lap belts only lap belts only
a falcon
Not if they did not come from the factory with seat belts. If they came form the factory with seat belts you are required to wear them.