Thanks gentlemen,
If I use the ST 51 NVA I will lose venturi space. Does that affect performance? Will the power be the same? How is the hole placed? I am planning on using it for a rehabilitated Flite Streak. It's one of the newer McCoys with the flames on the casing but it doesn't have much power. It starts easy and I have used it for sport flying. However, it was on a very heavy old Cosmic Wind. The Cosmic Wind has done much better with a B-40 that is now broken in and ready for a Nobler. I haven't gotten around to trying any of your suggestions yet, but since I have the ST NVA, I'm planning to use it.
Allen Eshleman