I'm holding off sheeting the inside for the sake of trial fitting everything first. The balsa for the top of the tunnel will definitely go on the top, I need all the room I can get! As you can see I needed to trim the bottom crossmembers where the landing gear plate is. Trimming these will allow ample room for the canister to rest completely inside the ring on the rubber bumpers.

The aircraft is not wide enough to get the exhaust exit tube down through a hole in the fuselage. I had to cut out a elongated section for the exit pipe to rotate down through. I could have cut the fuselage down at the center where the cowl ring mates up, but I didn't want to sacrifice the integrity of the fuse front.

Desert Aircraft warned not to cut the header pipe shorter than 10-1/2" or it might affect the performance of their engine. That limited me as far as being able to pull the canister forward and have it exit through the cowling. I did not want to cut the cowl ring either, Tom highly recommends leaving that in tact.