I had two coaches with Vortec 8.1 l, first on Chevy P30 the second on WorkHorse W22. We ran the second one for 110,000 miles in 8 years and the only failure was burned out exhaust donuts at about 85k miles. It had enough power and coupled with the Allison Tranny I never worried about getting where I was going in good time. over the 110k miles I probably added fewer than 5 quarts of oil altogether, mostly after pulling long grades. Techs told me that up to 1 qt every 1000 miles was within spec!
I did change to Bilsteins and had the coach alignment checked with change in tires. Alignment was performed in loaded condition per the manual. Alignment tech suggested I have toe in set to 0 deg for less wear and easier handling. It worked and I ran the coach that way for the last 75k miles. Did not get rivering on GY steer tires and wear was nice and even.
No info on the Ford product other than what I have read. Really sad the GM killed the vortec and then whoever killed WorkHorse. It was a great chassis from my experience.