[Big Dave]

Yeah, you gotta deal with that gap. I found my cab slants away at a seven degree angle. Yours is probably about the same angle, plus or minus. As a result I had to take a seven degree cut off the bottom of the front bulkhead, so the gap at the top doesn’t get too big. You might consider removing your center brake light fixture to enable you to scooch the bed cover tighter to the cab. I also fishscaled the bed cover versus the cab by about an eighth of an inch to allow for seasonal variation in the wood structure. Even plywood swells a little.

One thing I noticed right away was the reduction in wind noise in the cab of my truck. Energy was not being converted into noise. I occasionally have to take my fairing off and am amazed at the roar from the bed area.