I have a 95 Honda Civic that I was having problems with overheating.
It would push antifreeze out the coolant reservoir until it was out of
coolant. I ended up replacing the thermostat, water pump, fan temp
switch, and radiator cap but nothing fixed the problem. I then
started to suspect a coolant leak in the head gasket. I connected an
air hose to each cylinder using my compression tester hose. When I put
air pressure to #4 cylinder @ TDC, the coolant level in the radiator
would rise and spill out over the top of the radiator.

My question is, when I tear into the head gasket, how will I know if
it is the head gasket or a cracked head? Will it show signs on the
head gasket where it is leaking or will you be able to see a crack in
the head?

Also, should I do any other maintanance while I have the head off? The
car has 137,000 miles.