I've followed your trials and tribulations and really didn't have anything to add to all the suggestions but now that you seem to have hit a wall after all the work I think you are missing the obvious. Seeing water rush into and out of a radiator is not a good test of it's performance (as at least one other poster mentioned). To me--without a doubt your problem is the radiator. Having a nice shiny aluminum radiator is sexy -- but you may do just as well - or nearly so (aluminum does work well to transfer heat after all) - but cost wise I think a rodding out job or recore of your radiator will solve the problem. You need a good old fashioned radiator shop to help you. -- Dave