The IPD front sway bar for the 544 came in 2 sizes; a smaller bar if you only did just a front bar and a larger one if you did a rear bar too.

I used the smaller size on my 67 Duett, since the Duett has leaf rear susp and I didn't want to try to adapt the bar for a coil spring rear susp as on the sedan.

The problem that I ran into is that the mounting points on the chassis are spaced differently than on the sedan. If you try to use the mounting brackets supplied with the bar on the Duett, they will foul against the steering tie rods.
I did a work-around by using the factory mounts with the bar itself wrapped with several turns of inner tube. It works ok but on occasion, the inner tube seems to slip out of place. IPD didn't have a better solution to the problem at the time.

Good luck
...and best holiday greetings.
Bob