ok check this site out kerry, it is one that has been mentioned on the site before and i have one of their catalogs.
they have a section in my catalog with cab mounting hardware and they do have a part number for the mounting bolts, washers, and retainers along with urethane bushings.
i would give you part numbers but my book is for 80 - 86 models and might be different than 74 part numbers.
let us know how you make out !!
actually i went ahead and checked their site and couldnt find the parts you need but if you fill out the form for a catalog i would almost garauntee they will be in the catalog.