First, you can't get a Town Car with a 3.8L, they only came with V8's 5.0L & 4.6L and Mark VIII's only came with a 4.6L.
Second, if it's an 11.25" heck yeh, it's a great improvement over your stock converter!
Third, you need a different flex-plate because it won't bolt up to the one you have - you can get them off ebay for $25-$35 all the time. You need a flex-plate from a Mustang GT, Mark VIII, or Marauder - basically anything you listed in your list!
By all means, use it! You won't be disappointed! F63 is a great converter.
FWIW, I'm using a Mark VIII TC in my Bird right now which I believe is the same converter you have there.
Second, if it's an 11.25" heck yeh, it's a great improvement over your stock converter!
Third, you need a different flex-plate because it won't bolt up to the one you have - you can get them off ebay for $25-$35 all the time. You need a flex-plate from a Mustang GT, Mark VIII, or Marauder - basically anything you listed in your list!
By all means, use it! You won't be disappointed! F63 is a great converter.
FWIW, I'm using a Mark VIII TC in my Bird right now which I believe is the same converter you have there.