i have a 98 f150 4.6ltr longbed. the truck is 100% custom. i am in the middle of turning it into a shortbed. will a driveshaft out of a 4.2ltr shortbed work? or will i have to take my factory aluminum driveshaft and get it shortened?

also what are the fuel lines made of? stainless steel? and what size (outside diameter)? i think theyre 5/16" but can not remember.

i am new to the site and would greatly appreciate any help.. thanks in advance!!