Manfred, I plan to use the same engine on my PCM 109. I got the 4th kit that pat put out and so far Ive finished both wings. You might want to look around to see if anyone makes or will make a prop spacer extension for the engine to move it rearward to take advantage of the larger cowl area for concealment. Pat used a 3w75 in his prototype and used a 1" spacer. Also, He placed 4th at top gun with the 109 and won some other awards also. I bought a Zdz 40 to use in my miss america mustang to try the zdz's out and I must say I really like them, so the 80 is a natural for the 109. Do you plan to use the scale gear? Check my webpage for details on my construction.
Evan Q.
http://www.homestead.com/evoshangar/home.html