amd phenom ii 965

I currently have a pc with the listed specs: CPU: Phenom II x4 965 (OC to 3.9, can't go any higher) RAM: 8gb ddr3 1333 GPU: GTX 460 I was wondering which would be a better upgrade, upgrading the GPU to a 1650 super or changing the platform to AM4 (3100, 16gb DDR4 3600, and B550 motherboard)...