If you're getting the 5.9 out of a Ram truck, use the flex plate that is on the 5.9 now. As has been mentioned, oval one hole out so all 4 converter to flex plate bolts line up. Use the drivers side motor mount from the 318 in your Cuda. All you have to do is stack some flat washers to make a spacer. You'll see that there is a gap when you move it from the 318 to the 5.9....so 2 stacks of washers to fill the gap, and motor mount is done. Use the harmonic balancer that is on the 5.9 now also. Good luck to you. :)