Looking at the numbers you use - in this post and previous one - you seem to confuse two things: the aspect ratio of the picture and the aspect ratio of individual pixel.
The pixels that you initially work with - from your anamorphic video - are NOT square. They are stretched horizontally. Computer monitor always uses square pixels, therefore your numbers won't give you correct 16:9 picture. By changing the width/height in the layout property you simply change the number of pixels used.
Changing your encoding numbers should solve the problem. You may want to go to forums such as FCP to clarify the issue.
Yes, I know. but, is there another way to do this without encoding my videos again? I have hundreds of videos.
IMHO even if you come up with a trick that works on one particular platform, you would still face uncertainty how it would behave on multitude of hardware/software combinations out there. In other words you leave end user at the mercy of a chance.
So, I'd go back to video encoding, take one small sample, find the optimal parameters, and then let your computer do batch processing for all your videos.