I recently put the Harley stock mufflers back on my Vance and Hines true duals. I had the 510 gear drive cam put in and have a DFI installed. It has a Stage 1 air cleaner installed also. It seems to be running well, but I wonder if I should put the stock air cleaner back on. Bike is 2000 Roadking with Marelli fuel injection.

 

If it runs okay for you then leave it be.....

Especially if you have the DFO installed anlong with the Stage I....

You start restricting the Air Flow, you will be too rich to enjoy the ride.....