Bicycle Mechanics - Headset crown race taper

I need to replace headsets on some bikes from the 70s and 80s. I've noticed that the crown race on the older bikes is always tapered on the lower 1/3 to provide clearance for the brake bolt tapered spacer. All the current headsets seem to come with a crown race which is flat on the bottom and wouldn't be compatible with the brake on the older bikes. Is there a way to get around this, or do I need to find an older headset with a taper crown race?

Tough question!

I think the headset design changed because modern forks have a recessed area for the brake bolt spacer, whereas older road bike brakes used a spacer that sat on the outside. With the new brakes, the extra clearance of the old headsets isn't needed. So... I'm not sure if there are any headsets still made with the old style. On the other hand, I am kind of surprised that the old-style brakes won't fit at all with the new headsets. The clearance might be pretty tight, but have you actually tried it or measured it? I'm thinking if you added a washer or two to the brake bolt, you could definitely get enough clearance.

I haven't yet pulled off the old race or tried to install a new one or tried to measure precisely, but it looks like a definite mismatch unless I add a brake washer or grind off a bit of the brake spacer.

Well, I'd go with a washer on the brake... unless you can find a new headset that has enough clearance, which which be pretty hard to do unless you go around to a bunch of shops and physically measure their headsets.