Prothane motor mounts

[Edbert]

I did not change my frame brackets other than removing that small ancillary part on the driver's side, so based on my experience they WILL fit on a 67 unless my vert had different frame brackets from a coupe/fastback. I don't know why but somewhere over the years I seem to recall reading that they were different. I DID have to permanetly modify the factory frame mounts by cutting off the "tab" that helps support the factory engine mount. They will NOT fit with that tab left on, perhaps that is what you menat?

I compared these to the stock ones and they are within 0.10 of an inch in every dimension (that was as accurate as i could measure without calipers). I did not measure engine height but hood clearance does not seem to have changed.

The reason for using these is that I have broken stock mounts with a stock C-code engine, granted it was at the strip with a high RPM clutch dump but if they break with ~220fwhp then I don't see them living for long with ~400fwhp.

 

[mdjay]

As long as they look like this:

You're good to go.

 

[Edbert]

That's them, the photo Jay posted clearly shows the tab that needed to be cut off, it also shows that small additional bracket I mentioned on the top edge of both mounts. Anyone know what that is/was for?

 

[68restoman]

Another option is to modify a set of stockers with a through bolt, that's what I did on my 68 opentrack car and they've held up for several years so far...

Here's a couple of pictures from when I put them together, basically a cut off 1/2" Grade 5 bolt with a nylock nut left about 1/8 of a turn loose. They function like stock but resist pulling apart when torqued...

68Restoman

 

[Edbert]

I did that on an older Stang of mine back in the day, had to grind the crap outta the bolt head for clearance with the frame mount. That weakend them considerably even though I used a grade-8 bolt, far FAR stronger than the stockers though and worth the effort in my opinion.

 

[joesgt281]

I did not change my frame brackets other than removing that small ancillary part on the driver's side, so based on my experience they WILL fit on a 67 unless my vert had different frame brackets from a coupe/fastback.

Below is the research that led me to the presumption that the Prothane mounts won't work on my 67. From this, and other corroborating data, I think the 67s are unique.

By hawkrod on FoMoCo.com:
'67 Mustang SB motor mounts are special one year only parts. The rubber insulator sits at a different angle than the 68-70. the best thing to do is change the frame bracket to a 68-70 small block frame bracket. a side note is that the 67 style small block mounts were actually used on all 67-70 convertibles as well. if you hold a 67 and a 68 small block frame bracket side by side you will see why the insulator is different. there is one bolt hole drilled in a different spot which causes the frame bracket to sit at a shallower angle which is why the insulators are different. any good parts place will list 67 insulators as they are available but the 68's are cheaper and make it worth swapping the frame mounts (plus you can get urethane mounts for 68-70). you can force the 68 insulators onto the 67 mounts but they will fail earlier. it is easy to tell if you have the right parts as the bolts will slide right in with no effort. now having said all of that if your shock towers have moved at all the angles will no longer match up properly and complicates all of the assembly. if somebody tells you the parts are the same they have not looked it up in a Ford parts book or have compared the parts themselves. the national parts catalog (NPD) does not list the mounts correctly but the paddock catalog does. hawkrod

The following was posted by David Suesz over on FoMoCo.com and gives a clear picture of what Hawkrod was talking about:

It shows that the holes in the 67 frame brackets are higher than on a 68 and later. To maintain the same crankshaft centerline, the 67 mounts have to be "shorter" than the later ones. Unfortunately these unique mounts are not widely available. And if you put a mount from a later model on a 67, then the engine sits higher. It's my belief that the Prothane mounts are made for the later frame brackets.
The diagram identifies ALL verts as having the 67 style frame brackets up through 70 so, Mr. Edbert, I am confused about how you are able to use those Prothane mounts, unless your frame brackets had been changed.

Aint this fun

Joe

 

[Edbert]

Mr. Edbert, I am confused about how you are able to use those Prothane mounts, unless your frame brackets had been changed.

Me too, but they fit easily and you can see they're on there in the pictures.

I bought this car in 1987, there was a 20 year period where just about anything could have been done to it without my knowlege. At least the stuff you posted is good info, it also reinforces my recollection that vert mounts were different somehow, IIRC they tried to lower the CG to help prevent rollovers.

Jay, does your parts list show different brackets too?

Aint this fun

Actually yes, it kinda is, although my pocketbook might argue