I ran a Honda Prelude brake booster for over 17 years on my '72 Vega. I just mad a bracket that lined up with the Honda booster mounts and the Vega firewall to slightly angle the booster up and about 2 inches out.
I recently did a rear disk brake conversion and had to change the booster/master to a larger bore to increase fluid volume, otherwise I would still be running it.
This shot is from the wrong side, but you get an idea of the size
Cheers,
Tim