I'm happy to report that I found a 7" power brake booster that doesn't interfere with my inline 6 air cleaner. Larger boosters get in the way, but this one fits well. I wanted to keep my 1963 engine bay looking as original as possible.
A booster doesn't interfere with a V8 air cleaner because it's in the center of the engine bay.
I used the awesome firewall bracket made by CaptainFab. It made installation a breeze. I fabricated a simple connection for the Booster to PUSH ROD.
You can see ALL THE DETAILS on my BLOG.
LINK HERE.