place the injector depth the same as the OE injectors... the only way to do this is by machining the lower plenum to allow the top-feed injectors to be inset into it and the only way to machine it is to remove it from the engine.
I've had more than a few people express that they bought a WF rail because they did not like having to remove their lower plenum to install my fuel rails. So I've decided to accommodate the people who are not so concerned about injector depth and develop an optional bolt-on system. The upper plenum, throttle bracket and balance tube will still need clearance mods though.