Try TOHCan's method instead, or go one cylinder at a time. I just went through all this on a new 400. I do it by the firing order, starting at #1 and pushing the timing mark past the 0 by about 15 -20 degrees. Then, note the position of the four bolts on the crank pulley. Go 1/4 turn of the crank and do #8, then 1/4 turn and do #4, etc.
#1 is the driver's side front cylinder. The timing mark will be at TDC on either #1 or #6. Make sure you're starting with the right one. With the timing mark just past the TDC mark, both valves will be fully closed on #1. If both valves are fully closed on #6, you're one turn off.
