When I swapped the flywheel on my 748 for a lighter Nichols flywheel, I measured my alternator and used my cnc router to make an alternator holding tool that I designed. It made the job of torquing down the big alternator nut really easy.



Here's the alternator holding tool I made:





This will fit over the alternator and engage on the tabs on the front of it. It's not really needed to get the nut off - an impact wrench does that nicely.

Here it is loaded on the crankshaft, ready for the nut - the alternator holder tool is engaged on the alternator:



A shot of my setup while installing my flywheel. I just had to press down on the torque wrench, and I was good to go. The holding tool made this really easy.