Heads, Intake & Carb upgrade...

Welll, you didn't say what pistons you used putting together the +.030 shortblock, and that is going to determine a few things.
In the Mile High City, you need compression. Those X heads are open chamber and will drop the compression of a "stock" 318 down into the 7:1 range... not good, especially at altitude. Depending on your pistons, a later 302 head may be a better choice (or even a set of earlier 273/318 heads)- smaller chamber and flows reasonably well. You could then play with your cam specs a bit to get your Dynamic up into a reasonable range at your projected operating RPM, but that will also depend on your gearing and tire size...