My brake set up after the restoration was an angled 8" dual booster, a 1" bore cast iron master cylinder with the clevis pin one inch lower on the pedal to improve pedal ratio, 70's big single piston caliper discs up front and 11" Ford drums on the 9" rear axle. After driving this car with manual brakes for 20 odd years the new power brakes seemed OK but they were not as good as I was expecting . I decided to keep a casual eye out for a second hand Hydroboost unit, luckily one came up on ebay the same week. The kits that are available appeared to be ridiculously expensive so I looked for a cheaper route.
My booster came with the original master cylinder and I noticed that the booster push rod had a couple of mm pre-load on the master cylinder. My new M/C had a touch more than this so I trimmed the push rod to match. The inlet and outlet port AN6 adaptors are available here, top service from those people. My AN6 pressure hoses were made by Think automotive, always top service and highly recommended. The outlet port has an odd 5/16" barb fitting, AN6 versions of this are available here. They also have an ebay shop. With everything hooked up it was time to fire her up and bleed the system, instructions are here.
Another buttock clenching moment gingerly edging out of the garage into a busy road with new brakes but all seemed OK but the slightest touch on the brakes nearly sent me through the windscreen. Even worse was the fact that the pedal was slow to return and the brakes dragged for a couple of seconds after releasing the pedal. With a bit more research I found that this is a common problem on hydroboost conversions and is usually due to a return line flow restriction. The original return hose barb fitting had a tiny pin hole so I drilled this out to improve the flow. I also put a "T" junction into the steering box return line rather than my "U" shaped fitting. This solved the pedal return problem. I also read that the ideal is to have a separate return line from the hydroboost and the power steering box into a dual return power steering reservoir but that would have meant buying more parts.