My 49's running boards are a beer can's height at normal ride height. I've not had any ground clearance problems (I did scrape a speed bump I didn't see, but if I'm paying attention it isn't a problem)
But the real answer to your question isn't ride height - it's 'scrub line'.
Here's an explanation on the HAMB that might throw some light on the subject.......
https://www.jalopyjournal.com/forum/...ub-line.77804/