A female impersonator.. impersonator?

So I was a huge movie buff in the 80's.  VHS was new, ma and pa video rentals were on every corner.  There's an obscure movie with Jim Belushi and John Ritter.  It's sort of cheesy, doesn't have a very high IMDB rating, but it's entertaining for what it's worth.  There's one scene where Jim visits his parents, and his dad is a "transexual", which at the time wasn't widely talked.  As a kid, this shocked me a little, and of course one of the many things that got the gears turning (so if you're a guy, you can become a woman?)  Well, for whatever reason I decided to look this movie up.  Turns out the transexual is actually a woman playing a man being a woman.  Her name is Dyanne Thorne, and she was in a few movies before this one.  Sort of disappointing actually thinking this whole time it was a real transexual (they either dubbed the voice, or she did a really good job of impersonating).

Here's a clip of the scene:
https://www.youtube.com/watch?v=HCoLjp8GYZI