Envy Phoenix

Hello and thanks for reading this. I'm looking to upgrade my GPU from a decade old GTX 660 to something that can run 4K. What can my machine run? I've heard that it can handle a GTX 1060 but that a GTX 3060 would be bottlenecked by the CPU. Do you think my computer could run a GTX 2060? Any...

Because one of my monitors is old and only supports vga I cant connect them both to the GPU because the adapter is so big it blocks the original DVI port, so both screens cant connect simultaneously to the GPU. So before going to the Bios and changing stuff i wanted to know if its even possible...