Nice route. I do remember some nasty expansion cracks in the road last time I rode it, but it may have been repaved by now.
I'd highly recommend riding north on 395 over Deadman Summit to the June Lake loop. It's one of the nicest rides you can do in that area. If you don't want to ride that distance (50-60 miles), you could drive to the southern intersection of the June Lake Loop and 395, ride the loop both ways (~30 miles). The southern end of the JLL is about 15 miles north on 395 of the main road into Mammoth.