4/6 static drop, wondering about all kinds of clearance issues

[Scott76]

As the title said, 4.5/6 drop. 18" wheels, 285/40 tires all the way around. They are 27" in diameter. I'm starting to get concerned with numerous clearance issues, wanted to get some feedback from the board before I make changes. I've never done one of these trucks before (in fact this is my first 4 wheel project, coming from 20 years of bike building).

My headers are 3" from the ground at their lowest point. I know this is an easy fix with some shorties, but I have a lot of hours into welding up an X pipe system and would hate to cut it up if I don't need to.

It seems like there is about 2" of clearance from the top of the tire to the bottom of the wheel tub. How much travel does a 2" drop spring usually provide? Am I going to have to raise these tubs, or go to a different style of tub?

Pretty sure I'm going to have to roll the front fenders. The fender covers about the top 1" of the tire at it's very highest, which is exactly the look I wanted. I can pretty much fit my fingers between the fender and the tire when the wheel is straight.

I'm asking most of these questions, rather than just finding out for myself, because the truck is still not driving. It's running, but the interior is gutted and I'm looking at at least another month of work before it's drivable. I'm just getting a little overwhelmed over some of this stuff and would like to get some notes from the guys who have been there before.