The answer is, yes. Anytime you have a "closed" coolant system which is on almost all liquid cooled vehicles, you need to bleed the air out because air heats up faster than liquid and this will lead to air pockets and overheating. Too bad for the guy who blew his head gasket.
I also own an old Vette with a SBC and I remember having a tough time chasing air pockets in the system and trying to eliminate them. On my Vette, there is no overflow catch can to "refill" the system, so if you get an air pocket which caused the car to overheat and burb out fluid, you were screwed unless you had some extra coolant in the trunk.
On today's cars, even though we have the overflow tank, there is no way for the air to get out and the coolant on the reservior tank to get into the system unless you bleed off the air. when the system is finctioning properly, when the system gets hot, the radiator cap has pressurized spring that will relieve the system and allow the pressurized coolant to go into the overflow tank. then, when the system cools down, the system allows the fluid to return to the system once again. If there is air in the system, you will be applying more heat and pressure to the system than it was designed to handle and over time, it will blow through the weakest points, ie: gasket or thin spot in a hose. They make a special tool that looks like a radiator cap, but is designed to help you bleed the system. Anyone who has ever tried to bleed air out of a 2.2 4 cylinder Cavalier engine knows what I am talking about. I just changed my fluid this past weekend and bleeding the system was a breeze. Just fill the system at the radiator cap closest to the engine, not the one on the radiator itself (and don't fill the reservior up yet) and turn your heat on full blast to open up the heater core, then start the car and carefully watch the fluid level as bubbles come out. Top off as needed until the system starts to heat up, but don't shut the car off until you put the cap back on. Then, add a mixture of coolant and distilled water (50% mix) to the overfloow tank. The reason I said not to top off the coolant reservior first, is that if you do, the fluid will flow backwards into the system and instead of bleeding air out, the fluid level will rise and overflow the cap opening, causing you to get sprayed in the face with hot coolant while the engine is running. Not fun and a pain to clean upyour engine bay and fenders.
Hope that answers your question and gives you some info for future repairs.
