I am at Harbor Freight to pick up a jack and remembered that I wanted to get a big adjustable wrench for the pack nut but can't remember the size. The search function does not work well on my phone
I use a large pipe wrench and put a strip of old canvas on the nut to prevent gouging. Works fine.
Got it thanks A 14 inch adjustable opens to 2 1/8 just under $19:
You can make a wrench out of a flat piece of steel. In fact I made one out of aluminum. I gave it to another club member or I would post a picture of it. I make the 2 1/16 inch slots on each end at a different angle so that I could turn it in all positions of the flats.
I found the correct wrench at a swap meet and bought it, so didn't need the one I had made.
Nothing works like an original!
Get the wrench. If it is seized don't use anything longer or you might do what I did.
Use a Dremel and cut it off. Better to buy a new nut than a new manifold.