I have a 1999 Crown Victoria rear axle that is gone bad I need to know what other model cars form ford and year that will have the same axle in them

You'll need to remove the tag from the diff cover and compare ratio and locking or open to get the correct diff. I recommend going to a dismantler. They can tell you what fits as far as year and type. We replace A LOT of axles and bearings. The 8.8 just isn't up to the abuse but it is rebuildable. $300 an axle though.

If you are just changing the axle, then you can pull one out of any crown vic 1999-2002. I would suggest that when you change the axle, that you change the wheel bearing and wheel seal at the same time.

Good call! we always change both side bearings and seals even if we're only replacing bearings. Those axles are tough and often only require new bearings and seals. Don't forget the Friction Modifier and Synthetic gear oil!