TF big truck/little truck interchange

[joedoh]

I am looking at a 55 4400 and will be using it as a basis for a 1/2 ton build with a new bed and frame. I know on the AD stuff the 1 1/2 ton trucks have longer and wider front ends and I can see that this one definitely has larger wheel openings, but I have the chance to make a good deal by taking only what I want (mostly the cab and doors) and leave the rest for him to sell/scrap

what interchanges? headlight buckets? hood? hood hinges? what parts will I want to be sure to take and what can I leave behind? is the VIN on the frame somewhere? He has a title, and I wouldnt want someone to put the frame back on the road (ship of thesus)