Holy cow. And i thought 5 months was bad
It took me 18 months of acquiring parts to built my 7.3 so it could run in the early months of 2007.
My Duramax has been down for right at a year while I go through the chassis and I ordered the first round of parts for the big stuff 6 months before I started and didn't get the last bits of the first order until 6 months ago.
It took me two years to get the custom plungers and barrels that I designed from a machine shop that specializes in plungers and barrels (by they time they are rough machined, hardened, ground, sent to Europe for a special coating, shipped back, and fit - all while lumping them into other batches of parts going through similar processes while the economy was in the ****ter) - keep in mind that I am the parts originator, its not like I ordered them through a shop and could just call up and complain - they are my baby.
Custom means long lead times and patience. These parts for these trucks are often crafted one at a time or in very small production runs that must be fit into a schedule for all the operations to be completed in a certain order - that takes time. Generally speaking no one pays enough to get things in the timeline they think it should take.