Switch to horizontal induction?
Almost all the ram air systems need horizontal induction. Fitting a Rod Bower system to vertical induction is going to require a very significant cowl bulge.
My main complaint with the Bower system is that the filtered air is drawn from the warm lower cowl plenum, which gives a double hit on performance just when you need it most (take-off). First, it is about an inch lower manifold pressure, and it is warmer.
Search threads for discussions on alternative arrangements, mine draws filtered air from the cooling inlet ramp, and has only 1/4" loss compared to ram. But I do like having ram performance for cruise.
On balance, if/when i do it again, I will stick with Van's snorkel feeding the horizontal induction from the cooling inlet ramp through a filter, and just make nice round inlet lips around the filter box to help smooth flow into the filter. This arrangement gives manifold pressure within a few tenths of an inch of ram. It preserves the clean lines of the cowl.