Holley has been the undisputed leader in fuel systems for over 100 years. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Sniper EFI Intake Manifold. Sniper EFI Intake Manifold; Upper; Precision Fixtured And Welded For A Perfect Fit; Dual 4150 Flange; Silver;.