I've been hearing about this for a while now, but no one has said anything about what model year range of Crown Vics will interchange. IIRC you can replace the squirrel cage as well as the motor itself; the squirrel cage is a bit wider, which means it'll move more air, but it'll still physically fit.
So, does anyone know what model years to look at? Also, are there any replacement brands that are worth the time, or is this really a dealer-only item? Be nice to get something that'll move more air at a higher velocity...I'm a penguin who needs his air conditioning!!