If your bracket is the "L" shaped one I posted, you shouldn't have to make any modifications at all.
The bracket for engines without oil filters is just straight up and down. The "L" shaped on just positions the round part of the horn slightly forward so it doesn't hit the filter.
I'll take some better pictures from different angles if you want me to. Notice the bracket for the oil filter is slid back so that it contacts the manifold plenum.
