We build these LS to Hemi Throttle Body adapters in house on our CNC machines at Tapped Performance. These have a 82mm bore, that transitions to match up perfectly with a Holley high rise Hemi intake, adapter to throttle body sealing is done via "O" ring, includes hardware and "O" ring. We also build Hellcat (95mm) throttle body adapter separate to avoid length and short transitions behind TB.