Several customers  have mentioned that their Holley Sniper EFI System makes strange whistling or "splurping" sounds at mid-throttle when under load.  Some think the noise is kind of cool, the rest want to make it go away.  If you find yourself with a whistling Sniper EFI System and are in the second group, then customers have had good results with this 1/4-inch carburetor gasket from Mr. Gasket.

Note that the bore on the Sniper EFI System throttle body is 1 11/16 inches, a difference of a sixteenth of an inch.  For that reason, you will absolutely want to check throttle blade clearances and if that extra sixteenth of an inch might impact your performance plans then you may need to trim or this 0.185-inch thick Sniper EFI Sealing Plate or 1/2-inch 4-hole phenolic spacer may be a better match for you.