I am looking for a headset for my 1990 Trek 970. The only part I really need is the crown race. The headset that is on it is a Shimano Deore. My LBS could not find a Shimano headset from their suppliers so they sold me what they said was a cheap one. The cheap one is a Tange-Seiki TG-235 and the size is marked 30 27. This does not mean much to me. This is a threaded headset by the way. I would like to find just the crown race for this Shimano headset but if that fails, what do I ask/look for and what would be a good middle of the range ($) headset.