I got a 260z not long ago and i removed the block plug and no water came out! the water jacket was packed with mud! i poked a stick in it and finaly got it to drain then flushed it out with a hose. now i dont think i got it all out but since i have a freeze plug that needs replacing should i remove all the freeze plugs and flush the heck out of it? i have to remove the carbs to throw them in a large hole anyway. has anyone stumbled on to this before? i think it would run cooler without the mud. i plan on keeping anti freeze in it.