First Photo:
Here's a picture of the first stopping point when sliding the torque converter into the transmission (assuming it had been completely removed). The first stopping point can vary a little bit, so don't be too concerned if yours stops in a slightly different spot. Note that I drew a black marker line on the torque converter flange where the mounting bolts go. This line represents what would be the "fully seated" position of the flange when comparing the flange to the front mounting surface of the transmission when looking square at the side of the transmission (e.g. front mounting surface of transmission is perfectly in line with your line of site).
As this picture shows, the torque converter is not fully seated yet, as shown by the black line (straight up and down) on the flange which is roughly an inch away from the front mounting surface of the transmission:

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Second Photo:
From here, I make a "fishhook" with my pointer finger on one hand and suspend the tip of the torque converter in the "hook" to hold it's weight as if it were fully seated. This helps prevent the torque converter from binding when trying to seat it (makes seating easier). Then, I spin the torque converter clockwise a few times and then counter clock wise a few times to see if it will catch to get to the second stopping point (if a few spins don't do it, I do a few more. If it's still a no go, I pull the torque converter back out and put it back in in a different position). Here's a picture of the second stopping point (easiliy confused for fully seated), in which the black marker line is still about 1/4-1/2 inch away from being flush with mounting flange:

If you think the torque converter is fully seated (above photo) at the second stopping point, it's NOT! It needs to go another 1/4 to 1/2 inch.
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Third Photo:
To get the torque converter to fully seat, I spin in the opposite direction that just did that got it to seat in the 2nd stopping point. Then, when fully seated, it will look like this:

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Forth Photo:
Another angle of it fully seated, line of site no longer flush with transmission mounting surface, and you can see the black marker line a little better:

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Fifth Photo:
Yet another angle, fully seated:





















