A buddy of mine flies the 163 with a piped 91 2-stroke which is ample power. He's got Robart air retracts. I don't recall the wing being cut for anything, he did all that himself.

You might have problems fitting a 1.20 in the 163's nose. Have a look at either the wide-fuse version of the big smart move or the Ex 177. Send Sandy an e-mail and ask, I'm sure he'll recommend either of the two, the 163 might be a tad too small for such an engine.