[dsraven]

a lot of firewood to split before winter? yeah, but what are you gonna do AFTER lunch? lol.
if it were me, thinking of the stance and what to do about the rear, I would get it sitting on a flat level surface, drop the rear some to level it up to MY liking, figure out how much clearance room I need for the tires if the suspension were to bottom, ensure the wheel wells will accomodate that wheel movement, then get the truck over to the exhaust shop. I would do the alignment after the box is all done and installed so the stance is figured out with the final weight of the truck sitting on the wheels. all body panels are attached, seats, carpet, box wood, full tank of gas etc. that way the alignment is done when the truck is done. one thing to ensure is that the 4 link adjustments place the rear axle perpendicular to the frame and parallel to the front wheels (when aimed straight down the road) so there are no surprises when the alignment shop possibly adjusts things enough so that the 4 wheel alignment places the tires so that they are not centered in the wheel openings anymore. in order for the 4 wheel alignment to be done properly the truck needs to be loaded like it would be for the final ride height and stance. the stance has a bearing on the caster angle so if you get an alignment done now and then the rake angle changes later due to load applied or rake angle change, the alignment may be close but not quite right. if youre paying for an alignment, and it may be extra due to setting up a 4 link in the process, you might as well get it right the first time.
personally I like the truck with about 2deg of rake angle or simply sitting level. thats a tough one because sitting level means sitting low in the rear if you ever put anything in the box. unless you have air ride that self compensates for load.