Fishy,
You weren't dreaming, There have been a few different ones on here.
A couple have left the floor skin alone and removed the up and over part of the xmember and replaced it with a much stouter lower mount like on the link Longone posted above.
I question whether they have a good driveshaft angle unless the rear is jacked up.
here is a link to one of those threads.
http://www.forabodiesonly.com/mopar/showthread.php?t=41875&highlight=a-518+a518
I didnt like that and wanted to keep the strength going over the top, and to look similar to a factory install.
Because the floor was so perfect I didnt want to cut it if not necessary.
I measured, measured and triple measured to be sure that the trans was placed in at the same angle as the 727 I replaced.
I determined that in my case, the trans would point down below the diff a couple inches if I didnt cut the floor.
The up and over was kept as compact as possible, using two pieces of 1/8" flatstock (bent around an acetylene tank) and the sides are 5/16 round bar welded completely around all sides. I also removed about 3/4inch from the left side xmember between the torsion bar mount and the tranny mount holes.
That let me keep the tranny mount reinforcement thats inside the xmember intact.
