running out of breath in the 1/4 mile

As for the /6 fuel line, it makes NO sense to try to get by with a small line for what you are doing. The pump has a long pull from the tank as it is and a smaller line makes for more restriction. You don't want to do more upgrades and keep running up against any fuel issues; it impacts your jetting work and everything. 5/16" line minimum is pretty much standard practice; heck I used to run 5/16" in a 1.9L 130 HP 4 banger! And you have a 408?!? 3/8" line man! IMHO, 1/2" is overkill here.

No real silver bullets in this; it's one of those situations where you just gotta start trying this and that. As for the pickup, look at the sender/pickup as installed in the tank; if it looks like it is installed crooked, it's a good bet that the pickup is up from the bottom a bit.