There is no access to Kings Canyon National Park from US Highway 395. To get from the area east of the park to the area west of the park you have to take roads quite a bit north or south of the parks.
Access to the Cedar Grove part of Kings Canyon National Park is via the Kings Canyon Scenic Byway (also known as California Highway 180). This is a very pretty drive.
Sequoia National Park just started using its fleet of eight shuttle buses this year.
Kings Canyon doesn't have any shuttles at this point, so you are on your own.