RE: HOW-Where to drill to mount engine
I don't know what plane it is so can't be 100% sure but the offset center line is usually that way so when you put in the couple of degrees of engine thrust angle the crank shaft is centered in the cowl. On a kits plans they should show you or tell you how much right thrust or down thrust to put in. Most the time about two degrees so we offset the engine so the cowl will fit correctly.