I'm kinda on hold for the time being, till I get an offer on the 6.9. I hate to pull and it not let the new owner hear/see it run.
I was the same way.
I let about a hundred witnesses ride in and hear my old 6.9 start, run, rev, etc., and hesitated on pulling it until I had a buyer.
I had all kinds of big-eyed wishers, but no one with real cash money to hold under my nose.
I gave up and went ahead with the swap.
That was two-years-plus ago; and, the old 6.9 is STILL hanging on the chain-hoist that un-loaded it off the bed of my truck, with no more prospect of a new home than it had before.
SO, my advice is to yank that anemic dog as soon as possible and get that new life bolted in there, the sooner, the better.
After you once feel that surge of torque press you back into the seat-cushions, and realize you are going about four times as far on a gallon of fuel, you will take that old block to the scrap buyers with no regrets.
Here is the phone number of the ONLY place to get the engine mounts :
#480-325-6262 ask for Randy = Reliable Diesel
We are fixing to start a swap into an 88 F-450 as soon as a few minor details get ironed out.