My guess would be at least a 3-4 inch cowl unless you get a K member with engine drop. The MMFF coupe with the Lightning motor has a 5 inch cowl and they had to cut holes into it for the intake tubing and the top of the supercharger to peak through. That motor is a 5.4 though, and it's a tad bit taller than a 4.6, but with the supercharger i'd say you'll still need a good sized cowl.