SO it has proper press fit on output shaft?
The exact reluctors are hard to come by. I have some made just need to turn the ID so it has the proper press fit on the shaftI never bothered measure it. When i fitted the one for my camaro i tapped it on with a brass punch and hammer. The trans was already complete so i just unbolted the extension housing to fit it. Took a bit of time, it was tight. I imagine with the output shaft removed and using a press it would have went on easy. That's all i know. If you worried it's too loose put some loctite inside it then press it on.