Cooling issues, could use some advice

one thing that comes to mind is that the top of the radiator is lower than the top of the engines coolant passage, I don't know why I am thinking this could be a problem but I just read something in either hot rod or car craft where they fixed a guys overheating problems and this was one of the main issues. I cant remember how they fixed the problem (maybe with some sort of tank mounted higher up). So, if someone out there can remember this article, please refresh my poor memory....On a side note, I had a Belvedere that used to run hot all the time, well one day the core plug started to leak, it was then that I found out that the block was full of crud because the previous owner had never used any type of anti-freeze. I yanked the engine, pulled out all the core plugs and cleaned out the crud with a clothes hanger and running water, replaced the plugs. After that, the engine ran so cool that it would barely get into the heat range, and this was down in Florida where it gets hot.