Yes, the E was essentially a D with an aluminum swing arm.
As before the barrel & head slightly different. If you need it for Pre 78 you'll need to put a D barrel on.
You could apply for an exception (As per YZ250 & 360 B's) as if you are using the D frame the centrecases offered no gain as they were identical apart from the first 3 letter prefix.
That said I doubt if you would be pulled up on it.
