Hello, i have a friend that has an 89 305tbi. after he drive's about 15 miles at 60mph, and comes to a stop, he can hear what sounds like air pockets (loud surge noise) from the hose that goes from the intake to the heater core. he hasn't noticed any lose of coolant. i can't figure out where/how the air is getting trapped from the intake. the only thing i can think of is a head gasket is starting to leak when hot...any idea's? thanks, tom

does anybody think it may have a head gasket getting ready to blow?

Could be a head gasket leak. Do a compression test. If it's leaking, you'll find it.