Note that Rotella T6 5w40 CK-4 also is NOT on Ford's approved list for powerstrokes. Seems like Shell significantly reduced the phosphorous anti-wear content
in T6 when they reformulated the T6 for CK-4.
If you have steep hills, I'd avoid a sit down mower as someone else indicated above. Consider a stand-on mower like Wright, for a lower center of gravity on hills.
These have been on saltwater trailers. I've always replaced the hub (and thus the studs) after a stud(s) spins with the seized lug nut. I've never tried to replace only a stud - mainly because I would have no clue how.
Unfortunately, I've become an expert at getting seized lug nuts off trailers with a Dremel. Bolts typically start spinning with the seized lug nuts with the ones I've dealt with. Cut an X in top of the lug nut with the Dremel, and use cold chisel to peel down sides like peeling a banana...
Have an old SK 1/2 drive set I use regularly (see pix). The patent number on the ratchet was filed in 1939 and issued in 1941, so I'm guessing the set is from the 1940s. Anyone have an idea on the date for this set?