Is this a new engine? If it is I would wait till you have the rad in place and everything hooked up right. You will need to properly break in the cam. If it is not new forget about the hose and fire that baby up. It will not hurt a thing to run with out water or the PVC valve for a short period of time. However do not run it for more than a few minutes or it will get hot on you and you could damage it.
1973 Jeep CJ5- AMC 360, T181B, Scout Dana 300, Dana 30 Truetrac, Dana 44 Detroit Locker