You can still do inverted rows with
the Y dip bar option, but you can't position yourself as optimally — You have to either straddle one of the uprights (not recommended) or face away from the attachment, which might be difficultif space is limited outside the rack.
The X-3
Y dip bar is secured to an upright with a pin which allows you to quickly mount / dismount the dip station.
Inverted rows are one of the few areas where the X-3
Y dip bar attachment is less effective than the X-3 dip handles, despite being better overall.
You want the strongest and most durable dip attachment available —
the Y dip bar doesn't have a weight capacity rating listed.
Not exact matches
However, it is even more important with the
Y bar dip attachment because the handles extend much further out and all the weight will be on one corner of the rack as opposed to being spread between two uprights — thereby greatly increasing the possibility of the rack tipping if you're heavy and / or are doing weighted
dips.