I think it would be a good idea to prime it. On the other hand, you may not have that much to lose.
Priming it is pretty easy, but you have to make sure that you align the cam synchro correctly after you do it. The easiest way to do it is to take the cam synchro out, then remove the hexagonal drive shaft from the synchro. Put the drive shaft back in and spin it with a speed-wrench, 6" extension, and a hex socket that fits (5/16" or so). (I forget which direction it should spin.) You should feel some resistance as pressure builds. Then take the drive shaft back out (you have your pickup magnet handy, right?) and put it back in the synchro. If you noted the position of the cam synchro vane relative to the engine before you took everything apart, and you didn't turn the engine over with the synchro removed, then you can just put the vane where it was before, match the synchro housing to the block with the witness marks it left, and tighten it down.
The idea KMT listed is a decent halfway step. At least it won't fire with no oil present in the bearings.