ORIGINAL: dwango

I just placed an order for a CG Super Chipmunk and various accessories. Among these accessories was a one-piece pre-tapped OS engine mount for my OS FS-91 Surpass II four stroke. I've read that the Chipmunk requires some right-thrust and possibly some down-thrust. Do I have to be able to drill custom off-center holes in the engine mount to add the right-thrust, or is it set by the angle of the firewall? I'm asking because I'd cancel the OS engine mount order if its not going to be able to give me the required right-thrust (since the mount holes are pre-drilled).

TIA.