We build these LS to Hemi Hellcat (92mm) Throttle Body adapters in house on our CNC machines at Tapped Performance. These have a 95mm bore, matching up perfectly with a Holley high rise Hemi intake, adapter to throttle body sealing is done via "O" ring, includes hardware and "O" ring. Please note the 105mm adapter does not have a sealing O ring, seal is handled by gasket (not included). We also build the standard Hemi 5.7/6.4 throttle body adapter separate to avoid length and short transitions behind TB.