I drove this road 6 years ago or so. I've driven many FS roads in the Sierra from Sonora pass to Mammoth and this was one of the toughest, mostly because of the steepness. There was one (dry) creek crossing early on that was especially gnarly. But up-to-date info can be crucial. The road I drove my last trip, from Minaret Summit out to Deadman Pass, was way easier than the last time I drove it 3 years ago. They rerouted around the bad parts, or did some grading, in the interim. If they just regraded the Leavitt Lake road this spring, then it could make all the difference.
When are you going? I will be driving over the pass next weekend and could take a detour and check it out.
Bottom line: *I* wouldn't plan on going up it in my 2WDs, based on what I saw last time I went up it. YMMV.
That said, you might be better off parking along that road and walking up it (versus starting at Leavitt meadow). It's only a couple of miles to Leavitt Lake, I think. Or, consider starting at Sonora pass. Way less uphill from there.
P.S. It seems they graded this road in 2008, but maybe not since then? The first picture of the first stream crossing on this page is more like what I saw. Some of the other pictures (the wide, flat, smooth ones) may not do this route full justice.