Find your nearest John Deere dealer and get a few cans of Blitz Black in the spray cans. It's specifically made for frame and engine areas, resists oils, fuel, grease, and it's got a semi-gloss black finish that looks great even rattle canned. I did my engine bay, side of the dump box, and frame on my truck, and all of the exterior of my hot rod.
Blitz Black costs more, but way more durable than Krylon. For me it was one of those do it once for a little more or do it over again later for twice the price things.

1956 GMC 370 dump " 'Tater "
1970 VW Volksrod "the Black Bomber"
2007 Chevy Avalanche
2020 Jeep Cherokee Trailhawk,
2005 Harley Davidson FLHTCUI

I dig all cars, old and new, whether they were hammered out of American iron, German steel, or Japanese tin cans. Being unable to appreciate them all is missing out on a world of great things.
But thats just MY opinion! :P