I had a 72 lincoln. My favorite car. It had the barrel speedometer. It could go over 100 mph. And it actually got about 22 mpg on the highway. One time I hauled some 4x4 handi panels in the trunk. I miss that car.
If the brake light is on, I would be suspicious of the "Sure Brake" system failure. You better get a ford repair manual from that period so you can trouble shoot the problem, or the light will never go out. Sure Track is an antilock brake system standard on all 1973 Mark IV of the time. Rear wheels only. Drive the car to about 30 miles per hour and slam on the brakes you will feel a pulsating in the pedal and that might solve the problem also there is a 4 amp fuse you might replace in the fuse box.
