If you get the Mongoose, you will also need to use an MFi exhaust manifold, downpipe and provide a form of heatshield to protect the plastic inlet trunking by the spark plugs.

My XR3i EFI was the first one using the Mongoose system according to them as they never listed them for the EFI until that point. In their literature, it now states that you need to use the MFi manifold and downpipe.