I've flushed a many of radiators and have never had an airlock. Grant it that next time I do this I will warp my heads b/c of overheating so thanks for jinxing me. Nonetheless, when refilling, turn the heater on hot and on full blast or medium, poor coolant in slowly, when she tops off wait for the thermostat to open and slowly top off again. This is all done with the radiator cap off. To get the remaining air pockets out, gently squeeze the upper radiator hose. I can usually easily see the bubbles coming out, and when just coolant comes to the top and out your good to go. Check the coolant the next day and add until its full.

Here is a useful link over on NASIOC:
http://forums.nasioc.com/forums/show...hreadid=205802

There also may be information on:
www.endwrench.com
www.scoobymods.com

-Charles-