Sorry to hear that. I have spent a B-load of money also to get to the point I am at. There is not reason that you should have gotten zero pressure when using a 1” bore master cylinder when I am getting pressure with a 24mm bore master cylinder using a 2.75” bore Wilwood calipers.
Things to try if you haven’t already:
1. How was the F100 brake lines mounted? Back brakes on the front port and Front Brakes on the back port (nearest to the firewall). How are yours usually mounted on the Maverick? I would think that you will need to match the brakes lines to what the f100 had, if the Maverick was not set up like the F100.
2. If you didn’t bench bleed the master cylinder, take it off the firewall and bleed it on the bench to make sure you get a full piston stroke.
3. Make sure your bleeder screw, on the front calipers, is pointing strait up when mounted on the spindle to make sure all the air gets out. If not, remove from spindle, C-clamp the piston in the open position, clock the bleeder screw strait up, and then bleed that caliper.
4. Make sure you’re your brake pedal is adjusted as far back toward the drivers seat as possible. Unscrew the brake light switch as far as you can with out it falling out easily, and then adjust the brake pedal pushrod out toward the piston of the master cylinder.
5. Measure the piston stoke at the pushrod attachment point. I should have 7/8” to 1” of travel.
6. Make sure your brake pedal pushrod is just barely touching the back of the piston in the master cylinder. DO NOT PRELOAD the Master Cylinder piston.
7. The brake pedal pushrod should be inline with the master cylinders piston’s center line. If not inline, you will not the same pedal stroke and also wear out the master cylinder quicker.
My sister had a manual brake Maverick from the factory (25, or so, years ago). I cannot remember if it was front disc brakes or the year (I think 1976). But it had a very high pedal. I cannot remember how it stopped, but I know when the pedal released, it made a thud sound when returning to the depressed position.
Let me know what you find out.