Adding Node Version Help

Can I add a pveversion 4.4.128 node to a cluster running 4.4.44?
You mean "kernel version", prabbly. Should work - but Proxmox VE 4.4 has reached EOL, upgrade to latest Proxmox VE 5.x (5.3 currently). Also possible: cluster having nodes running at Proxmox VE 4.x and Proxmox VE 5.x