I bought a 'special' socket for tightening the big axle nut--unfortunately, it doesn't have a mandrel--years ago; with two Healeys I figured it was worth the money (about $40 IIRC) Since it's an eight-sided nut none of the domestic solutions will work, although you might be able to jam a 12-pt hub socket on it. I use a half-inch battery impact wrench, supposedly capable of over 200lb-ft, holding the nut on best I can, although I recall reading somewhere that 150lb-ft is spec. Next time I do this job I'll use a 150lb-ft limiting adapter (If I can keep everything on the nut). I bought this kit after I snapped a lug stud off a wheel on my farm disk with the impact wrench:
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For the wheel hub nuts, I figure they have equivalent purpose and strength to a disk-wheeled car's lug nuts, so about 80lb-ft should do it. IIRC, they're 7/16" fine and should be grade 8 equivalent, so 80 would actually be above max but typical for lug specs.