Aside from the bolt pattern to the engine, is the case dimensions of the 4L80E transmission in the XJR the same as a GM application?

I'm looking to do an XJR engine/ transmission transplant to a different car currently with a TH400 and I have a reasonably tight transmission tunnel clearances around the TH400 ( about 2" all around).

If I measure up a GM transmission at the junkyard will that be accurate for determining if the Jaguar version will fit?