Mark, do yourself a favor and give Mike a call when he gets back from Earlville. With the compression you're running spraying is nothing but playing with fire, especially when you are asking about something like a Top Shot.
One other thing you need to know about nitrous. The faster you are to start with, the less gain you will see. While a 50 shot will gain almost a full second on a 14 second car, you may only see a couple tenths, because your engine/drivetrain is more efficient to start with. If you're running a loose converter and a lot of gear, you'll run out of RPM way before the trap too.
