The 66 and 67 C4’s have different shifts
66 and older
1 was 1
2 started in 2nd and shifted to 3rd
D was normal
67 and newer
1 was 1
2 started in 1 and shifted to 2nd
D was normal
Now if you put the 67 valve body in the 66 transmission, it was a common thing to do.
1 was 1
2 was 2
D was normal
What a concept! … lol … good info, thanks.
Cause it blew up on the drag strip… 
Ford also had the FMX, C3, C4, C5, and C6 and were all 3 speed autos of the day, the bigger the number the stronger the transmission for the most part…
The AOD was Fords 1st OD (4 speed) transmission in 1980…
A little history on the 3 and 4 speed automatics for your viewing pleasure… lol
1980–1993 AOD—Ford’s first 4-speed automatic transmission, based on the FMX but with a torque-splitting feature.
Wow, thanks so much Nevada.
For a car this old it’s a stretch, but did your dad keep the owner’s manual? It could be in the glovebox or a folder dealing with the Mustang. As you can see from @Nevada_545’s response, it’s worth reading.
If you can’t remember which one to use, when you take off if it is slow and underpowered then move the shifter to the other “dot”… You can literally Feel the difference wen you accelerate from a stop… Another words, on a normal dry day, one is more fun then the other…
Here’s a copy of the owner’s manual for a ~66 Mustang:
http://onemanandhismustang.com/wp-content/uploads/2013/06/1966-owners-manual.pdf
My 63 lincoln is the same. Ford motor co. had some peculiar ideas in those days.
First, congratulations on your bequest, and condolences for your father.
Joining a Mustang club is a good idea. Even if you don’t want to learn about cars yourself, it will give you resources to mechanics who know not only older cars but these cars. Much has changed since '65 that a young mechanic may. not know.
As stated, black smoke on start up is a sign of excessive fuel. In this car that can be caused by excessively pumping the gas pedal before it starts, prolonged cranking to get it started or a misadjustment of the carburetor.
Your best bet would be to find a grey haired mechanic who could assess the cars total condition for you. A 60 year old car will never be able to compete with a modern vehicle on safety, reliability or comfort… The disc brake conversion would improve the stopping but that’s all. As a classic, an electronic fuel injection upgrade might also be available to improve starting and fuel management. Even after that, I would not recommend this car to be used as a daily driver.
I got the car back most of the problems seem resolved except one:
Brakes are much much better. I only have to press the brake pedal a little to feel the brake starting to work now.
Car starts up the first time every time even in the mornings.
Fuel leak and brake leak are fixed.
Although I paid $140 to have the engine cleaned and steamed, I still smell gas fumes when driving the car. I asked the shop what it could be and what could be done but they said it was typical for vintage cars but I’m not sure I buy this.
I have two other repair places selected to take the car to for this gasoline smell matter. One only works on vintage Mustangs, nothing else, and the other firm only works on vintage cars and hot rods.
Any idea what could be making such a strong smell of gasoline when driving? I just got a few fuel pump and rebuilt carburetor.
Thanks to everyone who has provided me with so much good info. I will be referring to this page for a long time to come.
I would check in the trunk, Mustangs are notorious for this.
since the tank is actually “inside” the car, not mounted below the trunk itself.
my first look would be the fuel inlet pipe, it connects the filler neck with the tank, they get old and crack…and that could be the fuel smell.
A 66 anything is not real tight. Could be poor door seals, poor window rubber seals. And so on. If you opened hood and sniffed motor you should not smell gas. You could have an exhaust leak and have a funny smell in car. Could be a rusty floor and you may not even know. I wouldn’t be surprised if mechanic would even say anything about your body underside condition.
You almost need to find a mustang club where a member can let you ride in their car. For comparison.
Only while driving? Gasoline leak odors are usually more noticeable while stopped or parked.
I forgot to mention. the tank will be under a rubber/vinyl (burtex) trunk mat that you will have to look under.
Here’s the gas tank (this one was painted red, but that’s the top of the tank). Note the rubber hose attaching the fuel filler pipe to the gas tank. Sniff around there to see if that’s the source of the odor. Otherwise, it could be gas fumes coming in from the engine compartment, see if there is any gas leaking around any of the rubber fuel lines connecting the fuel pump to the carb, and if any gas is leaking out of the fuel pump (there’s often a weep hole on the bottom of it).
Also - is the firewall between the engine and the passenger compartment in great shape? Any rubber grommets rotted out? Any rust holes?
My similar vintage Ford truck’s exhaust has a pretty noticeable gasoline odor the the first 5 minutes after a cold start. It’s a downside of carburetors is all. Ssually drive w/ window open, so can notice odor inside as well, when driving. After 5 minutes, gasoline odor is gone, both outside & inside.
If you notice it longer than 5 minutes … problems I’ve had over the years that could cause that
Note that it’s possible what you are noticing is just the remains of the prior leak. Give it a chance to all evaporate, may take a couple weeks.
Fuel smell could be any of the above, but if you only smell it with the engine running, I suspect that whoever rebuilt the carburetor did not set the float level correctly. On those old cars, I always set the float level intentionally low (high as it is measured upside down) so the fuel level is a little lower.
Two reasons for doing this. The rubber tip on the needle will compress a little over time raising the fuel level in the bowl and during hard cornering, less fuel is likely to splash out of the bowl.
One more thing, some of those carburetors used a plastic hard closed cell foam for a float instead of brass floats. The will waterlog (gaslog) over time and have to be replaced. Brass floats can also develop leaks. In both cases.
If you (or a friend) can remove the air cleaner completely, not just the filter inside, then idle the engine, sometimes you can see the gas coming out the vents in the top plate. That is proof the floats are either not adjusted properly or they are leaking and need to be replaced. Most of the time, all you have to do to remove the air cleaner is undo the wing nut on top, grab the sides and lift straight up.
It’s very strong when driving then in the garage I smell it a little when near the car.
The fuel tank is in the trunk? Where in the trunk?
