Starting a B without the clutch assembled

The reason I'd be inclined to reinstall them is that their presence and position on the right end of the crankshaft are what keeps the crank from moving left in the main bearings and keeps the rods centered on the wrist pins. Maybe it could move left far enough to chew up the oil line to the left main with the camshaft drive gear. Maybe it could bend a rod because of a lateral bind on the wrist pins though that's quite unlikely.

We all agree the absence of the clutch driver will cause it to shake rather stoutly. But allowing it to shake AND not anchor the crank to the right might allow that Chinaman named SUM TING WONG to wreak havoc inside the tractor! He's visited my shop and it looks like he's been to Wisconsin to vist Ralph too!

I'd put 'em back on and if the driver is loose and wants to rattle, wind some masking tape on the crank splines before you time it and put it on. It's never going to pull a load & it's just for safety and balance sake for a few minutes so where's the harm in that? This should allow you to safely start the engine to "scope it out" and likely keep Sum Ting Wong in somebody else's back yard!

I don't like to deliberately invite him in for a visit! He's quicker at breakin than I am at fixin! {:-)

My thoughts on it anyway.

If possible put the old worn one back on, large washers under the nut could even be used to tighten it up some back on farther because the clutch and other stuff is out of the way no need to worry about it binding up the facings.

If you don't have the old one the new could be used and may not suffer much spline damage since it won't be ran long or under load.

Plus just be extra careful of the added danger of getting wrapped up in it if your clothes catch on it.

And above all I hope I don't start another riot by trying to answer your questions. LOL