Could I substitute Anaheim chilies for Guajillo Chilies in a curry paste? I am trying to prepare a red curry paste, and the recipe calls for dried Guajillo chilies. I could not find them at any of my local stores, but I did find dried New Mexico and Anaheim chilies (which I've discovered after the fact are probably the same thing).

I read that the Anaheims are a bit less spicy than the Guajillos (500-2500 vs. 2500-5000 Scoville Units). I wanted to mention that I'm already aware of the difference in spiciness, because I am not especially concerned about that aspect of the comparison. The recipe also includes some considerably spicier peppers, so this part shouldn't make much difference.

I am more interested in the flavor. Since I am not familiar with Guajillo chilies, I do not know if their flavor is sufficiently similar to that of the ones I have for me to use them in the recipe.
Anaheims would be OK, but their flavor isn't just milder with respect to heat, but just generally weaker.  Pasilla would be closest in flavor.  Ancho is usually pretty easy to find and is fairly similar, just not as hot.  Chile de Arbol would be a good substitute, as would plain old cayenne if you can find dried cayenne peppers.  Heck, red pepper flakes (made from cayenne) might even do the trick, but getting the amount right would be tough.

Alternatively, Amazon (of course), Penzeys, and other online food stores sell dried guajillo chiles.  Then you won't have to worry about it!