most common problem with the fans is the relay. open the fuse box, and switch out the fan relay with another relay in there. if the fan still doesnt check on, splice the wires and run lead wires to the battery. if it still doesnt turn on, then the motor is shot and you need a new rad fan.

Now does it blow out of the reservoir when the engine heats up or pretty early before it even does?

I just had this same problem where it blows out the coolant tank. Turns out the overflow hose was worn out, easily flexible which is bad. When it tries to suck coolant back, the hose pinches shut. But of course it still forces coolant back in, causing it to overflow and bubble out. Now, the pipe and hose combo are discontinued. And getting the hose off to replace just the hose isnt going to go over so well for you.
I got a stainless steel fuel line with a flared end cut to the size of the pipe going straight up and down in the coolant tank. I got a new hose cut to twice the size of the original hose. Keep the bushing in there though. It should be fine. Just connect the hose and fuel line, use a couple clamps to hold everything in place, put the fuel line in the tank and the hose to the radiator. It works great. If the fan isnt the problem and its blowing out when the car warms up anyway.

Just keep us updated, and we can give more input for you.

 

The coolant isn't blowing out until the engine has warmed up, thats why I personally ruled out the Head gaskets, cracked heads, cracked block. I figured that if cylinder pressure was escaping into the water jacket it would start to empty the coolant as soon as I started the engine. Correct me if my logic is in someway flawed.

 

I have 3 relays labled Coolant Fan #1, Coolant Fan #2 and Coolant Fan #3 which one or all three?

 

Just switch them all out to test it, better safe than sorry. For all you know 2 could be bad, and switching them out one by one wouldnt tell you much then. I only have one big fan and one relay, so it was rather easy for me.

 

sounds like a bad radiator cap. call the local parts store and see if they can test your cap for you. most have a coolant pressure tester that can test the cap too. for piece of mind check the tube to the coolant reservoir under the battery. lol could be both. the steam/crossover pipe that goes from one head to the other at the back of the heads may be plugged. that would cause boil over.

 

go here 4th Gen LT1 F-Body Tech Aids and click number 12, also other good info on that site. home page is here 4th Gen LT1 F-Body Tech Aids

 

What craby said... My car did the same thing a few months ago. I looked at my cap and the rubber seal was cracked and the rubber was hard so i changed the cap and it solved my problem. However to accurately diagnose the cap have it pressure tested.