thats what I needed to hear Kirk, I had no idea that 8x4 was too big. Im use to bigger glow 2 strokes and saitos 4 strokes, so these smaller engines will teach me something, lol. I will do as you say and remove one head shim. Do you see that the 30%heli fuel will be a problem?
I will go and buy me a 7x4 and re-tach after I remove one head shim and see what we get.
Our club combat meet will require the use of the 8x3 combat prop, as you stated.
You da MAN Kirk!!