I bought the wrong transmission for my 66.

Last week I bought an 833 A body transmission 2.66 1st gear, rebuilt by Herb McCandless so I was told, the unit looks fantastic.
Turns out my 66 Dart has an 833od truck transmission? The tailshaft is longer. Has 2 mounting pads for the shifter and is currently using the front mounting pad. The rear pad doesn't even have holes or threads in it. Of course at this point that doesn't matter. Is what I have a truck trans? Did someone do the conversion with a truck transmission? why?

I think if I get a B/E 833 all should be good if I use the front mounting pad for my hurst. Is the B/E 833 the same as a truck 833?

If I install the McCandless A body trans, I will have to cut metal out of the tunnel, modify, not a big deal, have plenty of flex tape,sheet metal,etc. Looks like the shifter will just touch the bench seat if I do this. Looks like an 8 inch difference from A body mounting pad to what I currently have on my OD trans.

The A body transmission would move the shifter towards the back of the car. I always thought the shifter's current position was wanky the way it sits forward.

Also will need proper shift rods for A body. Get the 4.354 to 5.125 bearing retainer. Maybe I should just , no not yet, I was gonna say convert the whole thing to a v8 and just do it like I want it.

Icing on the cake is my $400 driveshaft would now be too short. damn. The trans I have is def a 833od, has aluminum body, and if it is a B/E then maybe I can just locate a good B/E non OD and sell this A body and call it a day. I would gladly like to have someone steer me in the right direction. Thank you.