head gasket

[fairlanegt427]

i fired up my comet yesterday with a 428.  the radiator cap was off and it was pushing a little water out the radiator a trail all the way out my shop door.  i fill water with a lift pump under vacuum to make sure all the air is out.  another friend of mine borrowed me the stant pressure tester kit so i started car and no pressure at all on the tester.  the only time that guage moved was when i would turn on the electric water pump then the guage would show just very litlle pressure.  i am, i think worried about this some what.  the car has cometic head gaskets on it and my friend told me that a person should use copper spray on gasket before putting on?  i asked cometic that a couple years ago when i assembled and they said to just put on the bare head gasket (no copper spray).  so thats what i did.   so now i am going to go to local semi parts dealer and buy a test kit for gases in the coolant system.  and then base my decision from their.  any body have problem like this and or give a guy some advice.  i really dont want to pull motor again with out making darn sure first.  engine is 428 with alum edelbrock heads.

[My427stang]

Is it a top and bottom tank radiator?

If so, they don't get filled to the top.  My technique is to fill the system, fire it, and when I see flow, fill it to almost the top to allow for the thermostat opening and let it circulate with no cap for a bit.

Then run it, let it cool and check level. It may have just been overfull. 

I may be missing something, but what you describe doesn't sound like it is a bad head gasket

[fairlanegt427]

i am thinking that it was over full also yesterday.  bacause i filled the sytem when car was cold drove it out the shop door and their was a trail behind me.  also as we know water expands when it gets warm.  i think i probably overfilled the system.  but i am still going to get the test kit to check for gases in the coolant to make darn sure.