My (current) guess is that it may be a
The Nanchang CJ-6 is an aircraft designed and built in China for use
by the People's Liberation Army Air Force (PLAAF) as a basic trainer.
- Round nose.
- Sufficient number airworthy.
- Rectangular wing shape.
- Main gear folds inwards and the nosegear backwards which seems to fit when I zoom in your pictures.
and they do airshows:
Coincidentally, the upper-left aircraft #43 also appears in your pictures (first picture, rightmost aircraft). Another below of her below:
update: as Cardinal said above, "This is likely Tiger Squadron, perhaps flying for the Israel Independence Day Festival over Rancho Park in mid May, as detailed on their Facebook page."