OH MAN !! What a bummer. This fellow bought the plane at a swap meet, some things assembled. The servo bays in the tail already had the covering cut out. I have edited this reply because I looked at the instructions again and there was mention of a "light engine".
Using the one front mounted servo, and the proposed control rod they showed, was not going to be what I would want on a plane and engine of this size, so I went with the tail servos. To me.... the guy selling the plane was not being straight with some information. He said he has had 4 of these ARF's and has had OS 160's on all. The firewall had 8 holes in it for 2 different motor mounts ? and a BIG part of the firewall cut away.... for muffler clearance I guess. I added ply to front and back of firewall to make it sturdy again. The thing is.... the cowl was cut for something other than an OS 160. One good thing is he has plenty of power with the 1.60. ... Thanks... lownslo.