71/72 engine mounts bracket vs 73

If you have read my rebuild thread, you know that I ran into a snag trying to use aftermarket urethane engine mounts in my '73. I have read that the mounts and perches are different, but since the aftermarket mounts are constructed similarly to the 73 mounts, I thought they might work. They didn't. I had to swap 72 brackets into my 73 to use them. Here are the differences between the two.

Aftermarket urethane vs 73 mount:



71/72 mounts on '73 perches in the car:





Passenger side 72 (painted) vs 73:







Driver side 72 (painted) vs 73:







And how it's supposed to look in the car:

I had a similar problem when I built my 71. I ordered motor mounts from the local parts house. Installed them and the hole wouldn't line up. After a little bitching they brought me out another set which looked the same BUT fit just fine.

Learned something new. I would have never thought they where different.

The engine mounts on the 73 can be two different heights depending on what month it was manufactured.

the first mount is a repop of the 71 429 mounts the second one is an original 71-72 302/351 mount and the red one is a 73 302/351 mount. Unfortunately I don't have an example of the I6 mounts to show you the difference with.

Okay I am confused here. You bought 72 engine mounts, then had to replace the mounting bases to 72 in your 73? Is there any replacements we found for these directly for a 73? Are there any ill effects from switching from 73 to an earlier year? Clearance issues ect?

I have a 73 built jan 1, 351 C, FMX, AC

Yes.

No, new '73 mounts are not made. There was a place that refurbished your originals. i wanted urethane, and I didn't want to wait for refurbished mounts.

No. Might gain some clearance over collapsed original mounts.

I was told the convertible car engine mounts were also different?

I was told the convertible car engine mounts were also different?

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I heard the same thing. That the 71-72 were different then the 73 and the vert were different the the hardtops. I will be needing the recipe for the my 1973 vert and hope someone can clarify.

The verts have taller mounts so that the drive shaft can clear the steel plates under the rear seats that Ford installed to stiffen the chassis.

The verts have taller mounts so that the drive shaft can clear the steel plates under the rear seats that Ford installed to stiffen the chassis.

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If you raised the motor and they all use the same trans mount - wouldn't that lower the drive shaft ?

Great topic totalled...great pictures as well.

I read through the post a couple of times, and understand we need to be cautious when replacing motor mounts.

the first mount is a repop of the 71 429 mounts the second one is an original 71-72 302/351 mount and the red one is a 73 302/351 mount. Unfortunately I don't have an example of the I6 mounts to show you the difference with.

Click to expand...

FWIW

My 73 convertible was born with the I6. It now has a 302 installed by my father in law. He has no recollection of EVER replacing a motor mount in any of his cars ever....on the other hand, Don of OMS says they are not close....go with Don.

that geometry would be my guess as well, but the verts mounts are slightly taller and i have been told that the reason is the plates. i havent been under my car in quite a while so i dont recall where the additional clearance is supposed to benefit the shaft.

So:

1. Dealing with 73 Mustang, non convertible.

2. Terms: Perch is mounted to the chassis.

Mount is on the motor.

You mention a bracket, but I think you mean perch.

Pin- This is the very special, hard, long bolt that runs from front to back and joins the perch to the mount. (Any sources for this piece?)

3. Difference between OEM mount and REPO mount is the OEM is one piece. Repo is 2 pieces bolted together. (Anyone got a welder?)

4. 1972 REPO mount "pin" holes do not line up with1973 OEM perch holes.

5. 1972 Repo Motor Mount and Perch can be replace 1973 Motor Mount and Perch. The engine will sit slightly lower, as the perch is shorter.

Could probably shim the engine up. You already have 4 bolts holding the mount together. What would be wrong with a few shims? Although you would need longer bolts...good luck with that.

Did I get this right?

the first mount is a repop of the 71 429 mounts the second one is an original 71-72 302/351 mount and the red one is a 73 302/351 mount. Unfortunately I don't have an example of the I6 mounts to show you the difference with.

Click to expand...

FWIW

My 73 convertible was born with the I6. It now has a 302 installed by my father in law. He has no recollection of EVER replacing a motor mount in any of his cars ever.

Click to expand...

Does the motor move around a lot

are there aftermarket parts? there are some substantial looking pieces out there, though i havent looked for 73. Ron Morris or TCP ?

I looked for replacement Mach 1 mounts and they are unavailable. You can take the 71-72 frame mounts and replace the motor mounts with the cheap (and available ) 71-72 motor mounts.

I guess I got lucky, both my motor mounts were broke and I went and got new ones from advanced auto parts, they had them in stock and they fit just fine. My car is a '72 though.