spasmatic: Thanks for the reply. I was thinking of trying that exact engine as well, in fact I just clipped out an advertisement for it from one of the rc magazines. How does the engine fit in the "as built" engine area? ( I don't have any dimensions of the engine)I would like to try and avoid doing any surgery, except strengthening up the firewall a bit. Do you have experience with gas engines or is this your first one? If you do, I may ask for some suggestions as this will be my first. It's funny you say that Bruce cautions against using a gas engine for the FK, when I wrote him asking for recommendations he didnt say anything about not using one, but that he didnt know what would be a good fit. His only mentioned concern was of the fit in the cowl area. For covering, I used Monokote...it works good for me and I know what I am doing LOL!