how many convertibles built?
How many 1966 Ford Thundrebird convertibles were manufactured in 1966? How many might still exist today?

The 1966 Ford Thunderbird finally showed an improvement in its engine and therefore in performance: a 7.0-liter, 428-ci V8 rated at 345 horsepower replaced the sputtering 6.4-liter 390-ci V8 rated at 315 horses.
Ford also played with its trim line a bit, replacing the Landau with the Town Landau. The Town trims featured formal-looking roofs, creating more of a cabin for the T-bird.
How many 1966 Ford Thundrebird convertibles were manufactured in 1966? How many might still exist today?
What newer engines can go in a 1966 thunderbird
In looking at pictures of 1966 Thunderbirds one descriptions said, "this a rare Q Code Landau". What does that mean?
I have a 66 VIN 6Y87Q123529 and I'd like to know how many Town Landau with 428 motor were built in 1966 and was this the only year for the 428 in the Thunderbird?