5:1 will make for MORE pedal travel. 67-69 PB pedal is 3:1 ratio.

If you have excessive travel, the first two things to check:
1. Rear brakes not adjusted properly. They need to be as tight as possible while not inducing drag.
2. Booster output shaft adjusted too short.

If you still have excessive travel after those two items are verified correct, you may have a bad internal valve in the booster

With four wheel discs, about 2” travel is expected until the pedal is hard.
Be sure all air is bled out.

I have 4-wheel discs, am using the stock 'manual' brake pedal.  I recently went from manual brake setup to a hydoboost power brakes system using the same pedal assembly, and, as MS noted, I do have some pedal movement before braking starts, that is to be expected.
Regarding SS brake fittings seating, I've found that putting a small amount of lubricant on the tool seating surface while making the double-flair, or bubble-flare, helped to make a better seat on the tubing.

MS wrote:

Follow up on the tube flares:
Especially on stainless, do not tighten the second half of the flare process real tight where it flattens the sides of the flare. Leave some compression room so the tube nut can seat the flare into the female fitting, doing the final part of the flare as it gets tightened into the fitting. If you crank the flare tool down real tight, it work hardens the flare and it will never seal. Same goes with other types of tubing.

Interesting.  I found I really had to crank down on the flair tool to get a proper seal with SS tubing.  With copper-nickel tubing I found that I needed not to tighten too much to get a proper seal as you stated.