Will the Mace CAI for VS v6 fit and work with the VS V8 as I bought a Mace CAI ages ago for my VS v6 and now I own a VS V8, or it’s totally different design/parts etc?

The main difference between the kits is that the V8 needs a section of a convoluted hose to join the throttle body to the filter adapter tube. This aside, the filter neck and filter adapter tubes are a little shorter on the VR-VS V6 CAI kit (CAI603) than the VR-VS V8 CAI kit (CAI803) however it should still work with the right length of convoluted hose.