wp_insert_post disable HTML filter

You could use call kses_remove_filters() before saving and call kses_init_filters() afterwards, but pay attention it will also remove filtering from title, excerpt and comments,
So what you should do is just unset the content filters.

// Post filtering
remove_filter('content_save_pre', 'wp_filter_post_kses');
remove_filter('content_filtered_save_pre', 'wp_filter_post_kses');

and after the post is saved

// Post filtering
add_filter('content_save_pre', 'wp_filter_post_kses');
add_filter('content_filtered_save_pre', 'wp_filter_post_kses');