I had the same problem when I was building mine.It looked like the ribs and spar was set up for cap strips and that is what I did.Ripped some 3/32 on my table saw about 7/16 of an inch and glued the suckers on.I think I will be alot happier when it comes time to cover.But now,in order to cut in alierons for the top wing,I am going to have a little more work.But it all smoothed out real nice.I mounted my OS 108 sideways and used a muffler made by Slimline with the two exhaust stacks coming out the bottom.Looks great coming out of the cowling.

Bill