yeah i didnt, i just drained the radiator.

 

Even if you drain the block, it still doesn't ALL come out. On our '98 I got the block drain out, but still took 3 or 4 drain/fills with distilled water before it came out CLEAR.

Not a big problem if you're just draining & putting in fresh antifreeze, but I wouldn't want to leave any flushing stuff in there...