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As many of us are aware, the drivers side ZF mount typically does not sit properly in its saddle.
My car exhibited this problem when I bought it, the previous owner hacked up the rearmost LH rubber bushing to make it fit.
I've installed new motor mounts and ZF bushings as part of an engine R&R, now it's time for reassembly.

Rather than modify the saddle or the ZF bushing, I'm thinking about sliding the engine/transmission forward by 1/8-1/4" or so by slotting the mounting holes in each engine mount pedestal...

Has anyone else tried this?
If so, how was the outcome?




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MJ, At the moment, I've got each mount in it's proper location...holes are biased to the front.  Another idea was to intentionally swap the pedestals left to right, then drill new mounting holes.  Something to think about...

If you look carefully at the previous photo, you can see that the rearmost rubber bushing had been modified, the ZF mounting ear was in hard contact with the saddle on the isolation.

On the RH side, all was well:




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Last edited by mpaschetto

Can you mill some material off the back face of the offending transmission mount?

I don’t think it would weaken it, as long as you maintain the structure where it mounts to the ZF.

You would have to push it out the rubber bushing before machining and then perhaps shorten it up a little bit prior to reinstall.



Last edited by rocky

Bending the steel ZF frame-ear(s) is by far the quickest, least invasive and most simple way to tweek the powertrain mounting position: no welders, drilling, cutting etc.  Incidentally, the rubber lip in the rear of the mount bushings is only there to prevent squeeks; if you have none, there's really no problem with leaving things as they are. Ear welding on the subframe was not micro-precise in Italy.

IMHO, most owners are interested in moving things backward for clearance. Shifting the powertrain forward very far risks driving the distributor cap and water pump pulley into the firewall or the steel access door. Adding to this thread, it's far easier to fiddle with the aluminum ZF mounts and the tranny itself if you remove the three studs holding each casting to the ZF and replace them with proper length metric bolts. In this case, the protruding studs are more difficult to work around than bolts, even though the threads go into an aluminum gear case.

Hi Guys,

Thanks for all of the suggestions.  It was a combination of modifications that got the engine-transmission unit in place, and fitting well:

1.  I bent the rear saddle ear a bit, that gained 1/16"
2.  I shaved a bit of material from the LH rear ZF bushing, that gained 1/16"
3.  I slotted the pedestal hole (LH side only) by 1/16"

Everything dropped into place easily, and all bolts installed into their respective locations hammers or pry bars required.  ;-)

Still plenty of distributor cap clearance:



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Very nice to see the run test. Very professional set up. Spent yesterday night  fitting a similar set of extractors into my car- - very very tight on the LHS. They are in . Barely in.

I am looking at increasing the final pipe run diameter to the rear resonators which is currently 2 inch. 

The front flange on your extractors looks 3 1/2 inch - what do you reduce down to for the rear pipe run - 2 1/2'" or 3" ? 

Any trouble threading that through to the rear without clobbering the drive shafts? Do you know what the maximum diameter you can reasonably squeeze through is ?


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  • IMG_2425: Don't drop any bolts you want....
@marlinjack posted:

...For what it's worth...I have 2-1/4" Pipes, on a Good Bounce/Jounce, they will rub against the Short Shaft, on one side of this car. I wanted to go with 2-1/2", the Pro Installer said He couldn't fit it in, to Clear. 3"?...Good Luck. MJ 

Marlin, I've personally seen it done (3" exhaust pipes) on a buddies Pantera, so I know it's possible.
My current 2-1/2" exhaust clears everything by at least 1/2", so I should be OK.

I already have a lovely 1/2 " depression that has developed very nicely on the top of the LHS side pipe under the short shaft which has now cracked clean though. 

The current pipes  are exhausted ( sorry )   .......and hence my question.  Can you recall if your friends car with the 3 inch exhaust used formed pipe  or was  it fabricated using short radius bends? 

I am looking at it and thinking it may have to be fabricated using  short radius fittings to get the required clearance. If I could get 3" in there the 3 1/2" extractor discharge diameter makes so much more sense. 


I can say 3” exhaust is definitely possible with round tubing.  You could also use round tube to oval tube back to round tube for the tight areas.  Dennis Quella gave me that tip.  If I remember correctly Stainless Headers offers products like that or can make what is needed.

By the way, your engine bay looks very nice Mike.


I had a 3" exhaust fabb'ed for my "pushbutton" '71. Tight but definitely doable. As I recall, since I used spherebar mounts for my anti-roll-bar, that raised the bar just enough to dimple my exhaust. Car was lower than stock and with a higher spring rate.

That aside, the only other insight I can offer is the 3" pipes may be louder. I ran mine into 2-chamber Flowmaster race "mufflers". Not recommended for the street. But, mpaschetto, looks like your engine can make use of the added flow!


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