Yes, I have.
The resulting simptom was
oil smoke out of one sidepipe.
Oil was being sucked into the intake passage under vacuum and the burned in the combustion chamber. Thanks to George Anderson's help troubleshooting over the phone the problem was easy to find and fix. This happend a couple of years ago; followed his advice on gaskets and sealers and haven't had any problem since. George really knows these engines!!
If he told me that an FE engine must be assembled while standing on one's head and whistling Dixie and juggling bowling pins.........That's how I'd do it.
Steve