[Steve M]

Here is a mistake I've made myself and I'm sure some others have as well.

Make absolutely sure your getting the right cylinder at the right valve pair.
I've done it where I tripled checked it and was still wrong. Lately it seems I've been getting the hang of it.
On the other hand the engine would not have started if I had it wrong. It may be worth the effort.

You also may want to check with the original maker of the cam as suggested above.