Plain Jane 73 Coupe

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canyonwlf7

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Feb 24, 2022
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My Car
Looking for a 71
But clean and all original and un-molested, I’ve got a buddy who is an old school Ford guy and can redo my motor, this 302 supposedly only has 38k miles, my question is if I upgrade the motor for more power will I need to obviously update to power disk brakes and power steering?
Thanks guys!
 
If you want to build upper body strength, keep the manual steering. Properly set up drum brakes with semi-metallic shoes will panic stop well but will not have the fade resistance of disc brakes. If you add significant power the rest of the drivetrain and cooling system will need to be upgraded for reliable use. How much power are you wanting to add? Chuck
 
No need to update to power steering or disc brakes just because you add more power. The power steering on these cars is really not the best thing in the world anyways, there is no road feel, and they tend to wander a bit. As for the brakes, I much prefer the disc brakes, but the drums will do as long as you do not plan to go road racing or something like that. I would certainly upgrade the brakes before I ever added power steering to the car.
 
A streetable yet fun to drive 347 with heads cam, intake, carb, etc should make well over 400 HP. You will need to upgrade the drivetrain for it to live behind that engine. Chuck
 
Apparently it does have power steering after all, what kind of upgrades would the transmission and rear end need?
 

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This is info I post on a lot of places whenever I see references to brake upgrades to disc. I feel it is important enough to bear repeating time and again.

You my already be aware of this, but in case you are not (or others reading this thread), it bear bringing this forth. The Master Cylinder (MC) for disc brakes is not the same as the MC for drum brakes, whether front disc or all disc. The first difference is the bore size of the MC is not always the same between the drum and disc brake systems. Second, the MC brake fluid reservoir chamber is larger for the disc brakes as the volume of brake fluid needed in the disc calipers is much greater than the volume of brake fluid in drum brake wheel cylinders. And most arguably the important difference is the Residual Pressure Check Valve (RPCV) needed for drum brake hydraulic fluid outlet(s) in the MC is NOT needed or wanted for disc brakes. Finally, never add any petroleum fluids to the brake system's hydraulic fluid, as it will cause the rubber seals and hoses to swell, requiring all hydraulic parts to be rebuilt or replaced. An aside, never let brake fluid get on painted surfaces, as it is an excellent paint remover.

If a brake system has its front drum brakes upgraded you need to make certain to remove the RPCV, otherwise the disc pad will be constantly dragging on the discs under pressure, which overheats the pads and rotor, causes excess wear of the pads, causes warping of the rotors, and impedes performance of the vehicle as there is a constant drag of the brake pads under pressure 100% of the time. If in doubt, replace the MC. The RPCV units are installed under the brass seat(s) of the brake fluid outlet port(s) if it/they are present. They are the little "flapper valves" made of rubber. If you have drum brakes the RPCV is critically needed.

Also, use only DOT2 or DOT3 brake fluid. Do not mix newer silicone based brake fluid with older DOT2 or DOT3 fluid. Never use DOT1 fluid as its boiling point is too low for use with disc brake systems.

Feel free to look at the attached file for more info, to include a graphics showing the correct orientation of the single piston brake calipers to ensure the brake system can be properly bled. If the calipers are installed on the incorrect side of the vehicle they will "fit," but you will never be able to bleed all the air from the calipers, and the brake pedal will feel mushy.
 

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Apparently it does have power steering after all, what kind of upgrades would the transmission and rear end need?
The 2.79:1 rear axle ratio is pretty steep, and will offer some good fuel mileage. But, it will also dog performance with low end and off-the-line acceleration no matter how powerful the engine is. I have found a 3.5:1 TractionLok rear end gear set offers a nice compromise for street performance, and highway speed driving. With 2.79:1 rear axle gears you will be spinning the engine at just under 2,000 RPM at 60 MPH in top gear (non-OD), more or less depending on the diameter of your tires. The same vehicle with 3.5:1 rear axle gears will spin the engine just under 3,000 RPM at 60 MPH, which tolerable. If you move to 4.11:1 rear axle gears you will have splendid low end performance, but the engine will be spinning at nearly 4,000 RPM at 60 MPH, which will sound like it is about to grenade at that speed.

One option is to install an OD tranny, or a GearVendors OD add-on unit. Our 73 Mach 1 has 3.5:1 TractionLok gears in it. We replaced the original 3 speed auto tranny with a later AOD unit. Now at 60 MPH in top (OD) gear we are once again turning just under 2,000 RPM at 60 MPH, making for a much more pleasant cruising vehicle, and retaining a very nice top end speed. We have the best of both worlds with the AOD. If anyone would like our vendor/parts lists just email me your request at [email protected]. I will also provide the list of YouTube inks showing our entire upgrade process, to include converting the Neutral Safety/Backup Light, switch to the AOD switch harness. It will be another week before I can send the files, as we are traveling at the time of this post being made.
 
How about keeping it untouched as much as possible as untouched cars are rare and getting rarer especially plain jane coupes. In good condition they drive nice. That is the best part of your car that I see that will start being erased even if it is only bolt on parts that can be changed back. Saves a lot of money and time which you will likely not get back
 
How about keeping it untouched as much as possible as untouched cars are rare and getting rarer especially plain jane coupes. In good condition they drive nice. That is the best part of your car that I see that will start being erased even if it is only bolt on parts that can be changed back. Saves a lot of money and time which you will likely not get back
Correct the cars main appeal to me is it’s untouched and basically all factory parts being all original, I don’t think adding on bolt on parts and rebuilding a 49 year old engine will detract from the value, not worried about getting my money back out I just want to enjoy it :)
 
If the engine needs rebuilding it needs to be rebuilt. Sometimes they just need gaskets and some refreshing on low mileage cars. I have a mostly untouched engine still going strong after 49 years with 83K miles. I don't think bolt on parts will detract from the value either as it seems most people like upgraded items, especially if you save any crucial original parts. We all should enjoy our cars as we like. I'm one of those ones which look for a complete experience of what 1973 was and prefer untouched cars as much as reasonable. I will always cherish them more than modified cars.
 
On a plain jane coupe adding performance parts should not in any way decrease it value, you could add value to it with the correct mods. I agree that the 2.79 gears need to go, and a 3.50 posi unit is a good compromise. Issue is your car has the 8" rear end and not the stronger 9" inch. For a street car that will not be going to the dragstrip with drag radials or slicks, and at or under 400 hp, the 8" will survive, but if you plan to add more power in the future, or you plan to race the car you should upgrade to a 9" rear end. The C4 trans is fine, it will just need a performance rebuild with a torque converter that matches the cam and a nice shift kit.
 
Here is the plain Jane, hoping the dark green pops a little more in the sun :)
 

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