I have a Borla EFI eight stack with 50mm throttle bodies. I have been on a waiting list trying to purchase the K&N filters with no production or delivery date. The price for all eight filters is $357. I just bought these from Amazon and they fit great and look good. They also have different diameters and the cost was $100 for all eight. I thought I pass this information since many are waiting for the K&Ns. I am in no way a vendor or sponsor and just wanted others to know.