Motorcycle Repair: Screamin Eagle® Stage I Kit for EFI Models, stock air filter, air filter element

Question
GREETINGS FROM THE OTHER SIDE OF LAKE ERIE!

I OWN A 03 FLHRCI [18000 KM] W/Screamin' Eagle EXHAUST SLIP-ONS/DEALER INSTALLED

I'M NOT SURE IF CALIBRATION WAS PERFORMED

I AM INTERESTED IN INSTALLING THE Screamin' Eagle® Stage I Kit for EFI Models
SEEMS TO BE A HIGH-FLOW TYPE OF KIT

LOOKING AT THE PARTS IN THE HARLEY CATALOG
THERE ISN'T MUCH THERE FOR MSRP CDN $227.95

AS A FRIEND SUGGESTED WOULD I GET THE SAME RESULT BY CUTTING A LARGER OPENING IN THE STOCK BREATHER CASING?
WOULD A DEALER CALIBRATION BE NECESSARY?

ANY OTHER PERFORMANCE ENHANCEMENTS [SPARK PLUGS?]
THAT YOU CAN SUGGEST SHORT OF A STAGE 2 KIT

THANKS FOR YOUR HELP

RIDE SAFE

GENE

Answer
Hi Gene.
 dont cut the stock air filter housing. It is not only the housing that is restrictive but also the air filter element.
Just put the screaming Beagle so called Hi-flow air filter kit on and be done with it. You will be throwing away money for the down load kit. It will not help.  JOHNNY