4-4.5" is about right from the
oil pan (Canton Racing in my case), but the Lakewood shatterproof bell-housing and flywheel coverplate will be lower than that unless you cut them down. Mine are cut to the same level as the
oil pan, and many others do the same..
Since the engine and trans. are set so far back from the front wheels it's not as vulnerable as you might think, but speed bumps are a killer, and you do need to be careful.
Adjustable Carrera-style coil-overs are nice in that you can adjust the ride height.