Your DOHC has two progressive main jets.
Not the same as the SOHC.
The jet that is the 40 is the idle jet.
With pods and exhaust I would go to a #42 idle jet.
Pods can be made to work just fine but just changing the mainjet is NOT the answer.
The fact that the slide is vacuum operated is not a problem.
If it was me I would go to the DOHC website so you can get the
correct jetting information by others with the same set up.
On a Roadstar Adventure.