The 42 crab cap had different wire looms. If you face the crab cap the 2,1,5,4 wires comes off the left. The 7,3,6,8, wires come off the right. That means that #3 and #5 have to cross over to get to their plug. The 42 looms have 2 openings the outside and one at the back end and one on the inside to allow the 5 and 3 to cross over the intake manifold. What most folks do that change to the crab cab is to make the crossover above the dizzy and feed into 46-48 looms. I will try the next post to display pics. John