At that time I didn't think to save the details for hump placement though. This time I will once it's mounted permanently in the right spot. I found that while the above link helped, it wasn't ideal for my car.
Two dimensions I do have at this point are measurements with the trans and shifter set up but sitting on the floor.
From the face of the trans where it meets the bellhousing, to the centre of the shifter handle with it in neutral is 18".
From the centre line of the transmission tailhousing (there's a seam in the casting) to the centre of the shifter handle, in neutral, is 3 1/8".
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars
I have some more dimensions but still not exact hump placement dimensions.
I measured to the centre of the shifter handle. The transmission is in neutral in the 1-2 gate, which is the middle gate.
I measured from the centre of the raised ridge just behind the seam sealer where the front of the floor pan seams together with the firewall/toe board.
I also measured from the centre of the raised ridge just in front of the seam sealer where the rear of the floor pan seams together with the floor panel that is under the back seat. I took a picture of each area that I mean. Both these ridges run from one side of the car to the other side.
The centre of the shifter at the base where it meets the shifter body is 10 7/8" back from the middle of the raised ridge at the front of the tunnel, and 46 1/8" forward of the middle of the raised ridge under the back seat.
Hopefully if anyone is needing to figure out the hole in the floor, this should help. If you have a hump, this should help you pick the right spot for it.