[DanEC]

I’m not entirely sure. When I dropped mine in I had the pressure plate/ flywheel bolted in place but left the bell housing off. Especially if you have one of the big, bulky Lakewood explosion proof bell housing I would pull it just to lessen the chance of dragging it against something in removal, although the type of bell housing doesn’t affect overall length any.

Related to Bill’s response I did not have any help so I was conservative.