The new radiator was not ran with old transmission. I am rebuilding the engine, and doing a few transmission mods, and don't know history of front cooler, so I was just trying to find out if it is worth flushing, or not. I purchased the M7B cooler. The radiator cooler, and the new M7B cooler, should be plenty sufficient. I don't plan on towing anything but maybe a utility trailer every now and then. I appreciate all the help and knowledge!