[bobcowan]

I've seen people put a petc ock in an empty intake manifold hole to accomplish the same thing. I put a 1/8" hole in the thermostat - never had any problem burping the system.

I also put petc ocks in in the block drain holes - right front and left rear. Makes it easy to drain the block without making a mess. I like the compressed air idea, I'll do that next time.