Hey Rusty, SBC (small beautiful cowl) is a tremendous improvement over BUC.  I was planning on designiing my cowl very similarly but was having problems with how to get all the air to exit.  I finally decided to try to run the air DOWN through the rad and out the back.  The rad will be getting sloppy second’s from the intercooler and oil cooler – but I am hoping that it works out anyway because those coolers don’t add a lot of heat to the incoming air.  I can’t tell you if it is going to work yet, but something to think about.