Welcome, BoldRider!
[MENTION=61614]verktyg[/MENTION] has knowledge that is unassailable. When he speaks, listen! Flick on the link, and you'll know all you need to know about stack height. For a cheat sheet, it's A+B (with bearings) from the picture [MENTION=33566]poprad[/MENTION] posted. Unless your Raleigh Competition's steer was shortened in it's lifetime, you should have no problem finding an "ISO" headset that works.
The very next thing you' learn in this forums is this: pictures or it didn't happen!
We're a very visual group, and love to drool over other's bikes. At some point you may want to meet some of us. When you get over your shyness, post your location.
Edit: your calculation is correct! But where are you measuring to?
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If someone tells you that you have enough bicycles and you don't need any more, stop talking to them. You don't need that kind of negativity in your life.
Last edited by gugie; 09-06-16 at 10:04 PM.