All the actions you would have to take to "slide" the tranny back far enough to get the converter on are everything you'd have to do to remove it. It has to be slide back at least 6-8 inches to get the converter snout into the tranny and make sure it's seated.
To do that, you'll have to:
Remove drive shaft
unbolt/remove crossmember to get it out of the way
unbolt tranny and slide back and down to clear everything (which will require a tranny jack, or at the very least a good floor jack and a couple of helpers.
Being careful not to bend or damage the dip stick tube, etc. etc.
Might as well just pull it. Or at the very least get the car very high on jack stands and drop it down as close to the floor on a jack as you can get it. You'll need a helper to balance the tranny if all you have is a floor jack.