What effect will heavy use have on the life of our truck?

If you read the maintenance booklet that came with your truck you’ll see they would categorize your usage as “severe duty” which calls for a more frequent maintenance schedule. Follow this as a minimum and your truck will love you for it. Well, not actually love you, but you get the picture.
Something I have always used and recommended for additional peace of mind is using a quality synthetic oil & filters. i.e. Amsoil