What a nightmare aligning front fenders & hoods to the AD cab. The darn things came off the assembly line with crummy fitting hoods! It gets even worse if parts have been mixed & matched over the years. I still run across the occasional truck that will not line up no matter what is done [ short of breakin' out with a big hammer & a cuttin' torch ].
Alignment is really simple...... Tony has the initial hood to cab sequence down. Next install all 200 bolts & nuts & screws on the entire front sheetmetal assembly loosely & slowly tighten each nut just alittle as you push & pull & lift & adjust & cuss at the sheetmetal fit . It could take a whole weekend with 3 people & you may not get it right. On the other hand I have put together a few trucks that fit perfect the first time I closed the hood. Good luck.