Because the cam gear turns at half engine speed, It doesn't matter if you choose 6 and 12, or 6 and 6 for to slide the gears on, prior to degreeing.
But before you drop the D in, just make sure you got the right cylinder at TDC compression. And it doesn't even matter which particular Cylinder is at TDC Compression, so long as you put the rotor under a tower, and call that tower by the same number as is the cylinder that is at TDC compression, then wire the cap accordingly. Oh and, the oil-pump drive has to be engaged.
There are only two reasons to do it per the book;
1) the factory precut Ignition wires are pretty short and some cylinders will not fit no matter how you juggle the wires around, and
2) is convention. Down the road if somebody takes the D out and isn't paying attention, then it is highly unlikely that he will get it back together right, cuz he's looking for the rotor to be under a certain tower with #1 at TDC compression.
