Well, Ford did use a couple of different length spacers behind the upper mount at the cylinder head, but I believe all EB's used the same one through all the years, so unless you got yours from a different donor engine, that's likely not the issue.
But frankly, your pulley sure looks to be pulled up close to the alternator body. Have you spun it by hand to make sure it's not scraping?
I can't remember if they all have them, but there is a washer (about 1/8-3/16 inch thick maybe) that goes behind the pulley on some alternators. That might be what's missing here.
However, taking that thought further, it doesn't really look like you have that much thread showing outside the nut as it is now.
Any chance you tried the pulley both ways? If not, maybe pull the nut and flip the pulley over to see if that fixes it.
If the pulley can't be spaced out, or a more suitable pulley can't be obtained, then the next step is to space out the upper mount to line things up.
The triangle bracket is somewhat flexible in that regard, and the lower mount can be bent to suit up to a point as well.
Good luck. Sorry about the hassle. Did we supply the pulley as well? I'm assuming yes, so another thought is to give us a call in the morning to see if there are any other pulleys we can compare measurements to. Just to make sure you did not get an oddball.
Paul