On the subject of 'burping' coolant systems, on the Supra I use the front-in-the-air technique with the addition of an additional header tank pushed in the rad filler neck. Its made from a Powerade soft drink bottle (that screws into the rad filler neck hole) with its bottom cut off, sort of a funnel.
It can be filled to near the top and add a further 8" of height to the cooling system encouraging air to come out.
Either that or vacuum the cooling system when empty, then stick a hose from a modified rad cap into the coolant to suck it in
