The traditional pullover is a great move because it works so much of your torso musculature all at once. Some do not feel their chest involvement as well as their back but it works both. Here is a hybrid move to help you better learn to feel your pectorals during the pullover as well as being a good stand alone exercise of its own.
The trick is with a standard pullover you tend to rely on your triceps as you fatigue or for parts of the range which you find tough. The separate dumbbells (as per a fly move) encourages you to stabilize your shoulders properly during the pullover aspect. Most people work a typical pullover a bit sloppy and just rely on the ribcage and abdominals to counter the stretch. Here because your arms are separate you need even control and to keep your pectorals involved. If anything the end result is a killer chest set.
This is tricky at first to control and coordinate so try a light set of dumbbells to get use to it (say 10 lbs). Make sure to focus on stabilizing your shoulders and don’t try to go too deep into the stretch right off the bat. You can also perform this laying on the floor to learn, this provides you a safe depth to stop at and rest if need be. The bench in the video is useful because it can be set with a mild incline which helps relax your neck and upper back.
Be well, be strong,
Andrew and Tierney