I haven't fished the Wissahickon so I don't know the conditions. Generally though, I would not use a strike indicator if I can see the fly or I can see the tippet "twitch" with a strike. An indicator gets in the way of presentation (as MKern points out). IMHO lead on the tippet does also.
If you can get away with out the extra stuff, you'll be able to present that bugger in an amazingly wide variety of ways. Try all of the following:
Upstream on a deaddrift
Upstream, stripped back down a bit faster than the current.
Highstick nymphing.
To the "quarters" i.e. quartering upstream, downstream and I include directly across the stream in this.
Swung downstream like a wetfly
And just about any other way you can put this fly in front of a trout! The only other fly that is as versitlie is the muddler minnow.
Try getting some weighted buggers, rather than putting weight on the tippet. You can still present the bugger in all the ways I mention with the weight, but I find it easier and better to have the fly weighted instead.
Best of luck!! :-D
Padraic