http://www.chiefaircraft.com/rcmsec/...gnum.html#xl91

149.99 and Magnum makes good engines. If a few bucks doesn't concern you then get a Saito instead of the O.S. or grab the 1.20 Mag

A warbird isn't a 3D'r so a little difference in power isn't going to make as much difference. The Mag might have a touch less power than the OS.

Good Luck,