ORIGINAL: VincentJ
Moving the firewall back isn't as hard as you might think especially during the building process and not as an afterthought. Make sure that you use a piece of ply of adaquate thickness 1/4'' at the bare minimumm and not more than 1/2''. Be sure to use a good quality Birch ply and to use epoxy for the adhesive. In addition to the epoxy it would be wise to pin the sides of the firewall with wood dowels. I used 4 or 5 on each side on mine. As for the right thrust putting 1 1/2-2 degrees right thrust wouldn't hurt anything. It may help offset the thrust of the engine on takeoff to minimize the input of right rudder. I had to move mine back as well, I used a DLE-20 on mine (wished I had used the DLE30). Hope this helps and good luck.
I was thinking about a Zenoah G26 so I wouldn't have to do as much modification but with the width of that motor I think I'd have to cut holes in the cowl for it to fit which I don't want to do. My local hobby shop has regular lite ply but I didn't birch when I was there last. Since I'll have to move the firewall so far back (somewhere around 1.5") I guess I'll have to leave the lite ply pieces as cheeks and put doublers on them so I'll still have the length in the nose to attach the cowl to. Do you happen to have any more pics of the music wire you used down your "a pillars" to reinforce the forward cabin?