[rotorwrench]

I'm not sure how the divergence in the exhaust ducting is going to affect things in there. The velocity decreases a bit until it gets to the port where it will speed back up again. This is where I know I missed out on the engineering education I probably should've had. Maybe I worry too much but it seems it might have an effect on scavenging. I'm no rocket scientist though and it might be OK. Maybe others who have played with this stuff can give their ideas. Ford didn't have a very straight duct in there but it was uniform in cross sectional area pretty much all the way through. A drop in the roof proportionate to the drop on the floor might be necessary.

It will likely improve things on the intake side though since it should increase the velocity at a point where that could be an advantage.