Actually they say it has more than just an extra planetary: "The main improvement of interest to hot rodders is the 4L65E’s five-pinion planetary carrier that replaced the 4L60E’s four-pinion. More pinion gears help to spread the load, allowing 4L65E transmissions to handle more torque than their 4L60E brethren. Additionally, a better 3-4 clutch, improved input shaft, and a deeper pan for more fluid were added."well im off to look at my rpo.
but in the mean time, according to this page, m30 was 4l60e.
the 4l65e just means an extra planetary, ...5 instead of 4.
www.hotrod.com/articles/spotters-guide-turbo-hydramatic-transmissions