I'm pretty sure it isn't a tuning issue. I'm also maybe leaning towards a slight vacuum leak. It would make sense because I didn't lube the lower injector o-rings or replace them when I did my gaskets. I'm 99.9999% sure my gaskets are sealed perfectly.

Vacuum lines look good. I have a set of six o-rings and I think I'll replace all the lowers this weekend if I get a chance. That fuel smell last weekend in the #2/#4 area bothers me, but there's no visible leak that I can find.