Motor Mount Bracket CONFUSION

[anlauto]

Okay....today I'm having a huge brain fart and can not figure out what the problem is. I'm working on a 1971 340. I have the mounts shown in the picture below (borrowed from the internet)
My passenger side mount bracket is the same as the one pictured (OK) but when you hold it up to the engine only two of the three bolt holes line up  What am I missing, what's the deal ? All engines are casted the same with two holes at the front, one at the rear...

[anlauto]

This is what I have...Holding the mount in place on the passenger side, only two holes line up ???

[Cuda Cody]

I'll check when I get home and see if I have a set of 340 mounts that I can measure for you.

[Cuda Cody]

This thread on Moparts has some good photos...  even though it's "A" body related, it might show the hole locations.

https://board.moparts.org/ubbthreads/ubbthreads.php/topics/1947246/re-1971-340-engine-mount.html

[anlauto]

That would be great Cody, thanks....I found a picture of the original mount from that last AAR I just did...it appears the same yet has four holes...

I can drill an extra hole in the one I have, but then would be worried whether or not the offset of the rubber isolator is correct etc...

[Mrbill426]

I took these (only) pics of my 72 mounts before the block went to the machine shop FIVE weeks ago; hope it helps.

[Mrbill426]

If you need a measurement let me know; the mounts are still here.

[Scooter]

All the mounts I have seen, the passenger side has 4 holes. Even the aftermarket parts... that is odd.

[Mrbill426]

Yes mine does... unused too.

All the mounts I have seen, the passenger side has 4 holes. Even the aftermarket parts... that is odd.

[71vert340]

 Here's a photo of the passenger side engine mount on my 71 340.
Terry

[anlauto]

Where I'm confused is with the fact I've found plenty of pictures on the internet showing the one with three holes that I have. Exactly the same as the one shown here marked (OK). I know the driver's side is unique like shown in the picture, so the one marked (OK) has to be the passenger side, but when you hold it in place, only two of the three holes line up   So what could it be for ? All the engine blocks I'm aware of, big and small, have the two holes casted at the front on both sides ???

[anlauto]

I'm pretty sure I can get away with just drilling an extra hole 

[Mrbill426]

So the two holes that are on the same plane, across the mount from each other are fine but the stand alone hole is the one that is off?  Sorry, trying to wrap my head around the disparity.

I'm pretty sure I can get away with just drilling an extra hole 

[anlauto]

So the two holes that are on the same plane, across the mount from each other are fine but the stand alone hole is the one that is off?  Sorry, trying to wrap my head around the disparity.

I'm pretty sure I can get away with just drilling an extra hole 

Yea, basically the "stand alone" hole, or lower hole should be on the other side of the mount...The two top holes line up with the engine casting.

[Mrbill426]

Got it Sir 
I can measure mine if you like but probably more accurate for you to mark and drill.  Go to be a factory defect.

So the two holes that are on the same plane, across the mount from each other are fine but the stand alone hole is the one that is off?  Sorry, trying to wrap my head around the disparity.

I'm pretty sure I can get away with just drilling an extra hole 

Yea, basically the "stand alone" hole, or lower hole should be on the other side of the mount...The two top holes line up with the engine casting.