You talked me into it. 727 to a 904

It's not weird, Mopar (and every other company) made changes over the yrs that they felt improved them. The larger higher capacity sprague is one of the improvements. The more transmission work you do the more differences you'll find in them from year to year. Makes it tough sometimes finding parts

Is the 88 a lockup or non-lockup version?

Lock up, style. The valve body has the cross over tube and the input shaft is hollow.