Something that I intend to get around to one day. Make my own airbox that is. I had the same thoughts after reading that book.
I suppose if you are stuck with the frame with the higher brace then moving the airbox into the space that is occupied by the coolant tank and then extending down around the injectors may have some decent benefits to the engine etc.
I suppose the other option is to have the brace in the frame lowered but If welding and frame building is not a strong point, then its something best left to people that are in the know. Thing is it could end up being a lot of work for not a lot in return. Well not without lots of other work to set it up etc.
I will get around to it on my Track bike one day maybe. If it worked out I would do the same thing on the sps. For now though, the track bike is being worked on with other things in mind so this project will have to get in line.
Just had a quick read of the site shown above. Pretty damn good. Lots of info if you are interested in building and putting the bikes together properly.
Good to read that the guy wanted to do the tinkering himself and learn how the engine works and how to put one together right.
Makes a change from, " I bought this bit of **** and bolted it on."