67-76 floor into a 65...

Keep in mind, that some of those ribs on the sides of the OD unit can be trimmed down or cut off. That alone may mean being able to use an OD transmission within the confines of a stock later floor pan like the one you are adapting to your early A. It is possible to put an A518 into an E body without cutting the floor pan or crossmember, by cutting and trimming the ribs. I know that's an apples to oranges comparison, but with the crossmember mods you're doing....it may gain you enough room to get one in there and not have to bulge out the floor pan to where it's a pain in the *** to get carpet to fit. If you can get a 727 to fit, chances are you can get at least an A500 in there. An A518 is longer than an A500.