Matt and HB,
Thank you for your responses. You both suggested NAPA for the lug nuts so I'll check with them.
I have the 17.5 rims on my 3600.
My bottle jack and little lug wrench looks so original and fits neatly under the bracket spring. However, as you say Matt, it does seem an undersized lug wrench and the jack is worthless on its own for jacking up the truck. So I was scratching my head; an original factory jack that is useless on the vehicle it comes on?? Looks like I have my answer, a puzzling yes.
So good news: I have original equipment!
A lil' bad news: It doesn't work.
I bet there were a few upset and stranded owners back in the day when they got their first flat tire and realized they couldn't jack up their truck far enough to change the tire with the factory supplied jack.
Thanks again,
James