About one year ago I rebuilt my engine, heads off new piston rings and bearings on con rods and crankshaft plus TC parts ( Cloyes ). I never had the chance to put a different engine in having said that it is very low milage anyway 40k miles only and in good nick. It is a job 2 identical to yours even the colour. After all that work it developed a big oil leak between engine and transmission.
So I pulled the engine again and finished it yesterday so everything is really fresh in my memory! Found upper pan gasket had split both sides of rear crankshaft cap. I had bought a cheap ( DNJ ) lower gasket set big mistake. This time Felpro, with Ford front and rear crankshaft oil seals (rear sleeved )
Also had scraping noise at front TC took out Cloyes parts and changed all to Ford, I'm paying for my mistakes!
Your egr tube will need 27 mm open spanner and it's still difficult to get a perfect purchase on that nut. I'd suggest the more you can take off engine the better, especially heads to get to engine to transmission bolts. Plus blower motor, rad etc etc. I don't know if leaving left header and egr tube on will clear everything.
I found this helpful, I supported transmission on torsion bars, this kept transmission in exactly same position and could push ST back and to. Used a mango tree to lift engine so ST had to move.
If your engine is salvageable it is obviously your most economically viable option, we'll just have to wait to see what the tear down reveals.