Azalea might work -- talk to the rangers at the Kings Canyon Visitors Center. Otherwise, there is an adequate full hookup park in Squaw Valley, near Dunlap. But it is quite a drive from there into the park.
The other option is the RV park in Three Rivers, at the south end of the park. Again, a bit of a drive up to Lodgepole, but not impossible.
One more thought -- check into Potwisha Campground near the south entrance on 198. It might be able to fit big rigs --again, the rangers at the Ash Mtn Visitors Center will be your best bet.
Finally, if you are feeling brave, there is some boondocking/dry camping at Big Meadows in the Horse Corral area that might fit a big rig. Talk to the Sequoia Natl Forest Rangers in the Dunlap office -- they are in charge of the Hume Lake Ranger District.
All of these options will be crowded on weekends -- try to time your arrival for mid-week.
Good luck!
2012 Fun Finder X-139 "Boondock Style" (axle-flipped and extra insulation)
2013 Toyota Tacoma Off-Road (semi-beefy tires and components)
Our trips -- pix and textAbout our trailer"A journey of a thousand miles begins with a single list."