318 cam change

It doesnt really matter where the rotor is pointing, so long as its under the tower of whatever wire is going to the cylinder that you have indexed to TDC compression.
Now it customary to have the rotor pointing to the front intake manifold bolt, on the drivers side,because that locates the #1 plugwire tower(if so marked) in the proper orientation, and the vacuum advance can will also then be positioned in a way that makes timing changes easy. But like I said you can put it anywhere you want.