Originally Posted by Bob Dopolina

What the heck are you guys talking about?

Changing a top cap or a spacer should not require changing a headset unless there is some proprietary wierdness going on.

Are you talking about a cap that fits over the bearings and under the spacers? Some of those have a seal in the bearing side of the cap and can be quite tall.

If so, roll into a shop. They should have a drawer of various headset parts and you should be able to find one that works.

Edit: I see what you are talking about now. As mentioned, if you have a race built into the cap you need to be mindful of the bearing/race angles.