Kenny!!!
As you know, more than one way to skin a cat, especially exterior lights.
Here is the link to the FAA regs Whelen posts on their site.
https://www.whelen.com/pb/Aviation/S...%20Systems.pdf
With no tail strobe or light, you need to mount your tip lights to have the rear quarters covered as depicted. This is definitely a grey area as I have seen just about every iteration you can imagine over the years.
Suffice to say, if the DAR inspector has an issue when he inspects your -7, he will tell you. The lights should be mounted mid-span just below the edge tip on the W-415's. I can't give dimensions, but there are many examples flying and on the web, here are a few...
https://www.google.com/search?biw=25...rh7tbwvj94z_M:
U Da man!!
V/R
Smokey