make sure that the covering is ironed down tight next to where you've removed for gluing. Cock the stab a little and use the tip of your hobby knife to hold down the covering to start the stab in. I think the OS 46FX is plenty of power so the AX should be even better. If the Mag is heavier go for it because the plane will come out tail heavy. I had to add several ounces to get it at 4 1/2 inches.