I bought a ibec for one of my planes, nice product and works well but I wont buy another, why, because simply I have another three gassers running a single homemade life pack for ignition and rx with no stepdown for rx and I have had zero issues. I am on 2.4 ghz..

I understand the ignition does not require any more than 4.8v, that I will not get a better spark, my ignition will fail prematurely bla bla bla.

If worried about the 6.6 volts then as someonehas said fit a diode, been there done that too, works well for a 0.7 volt drop, but I dont even bother doing that now.