Zuffa era: The biggest weight difference between two fighters?

The title is too short to get it all in there.
I just re-watched Machida vs Penn.

I just wondered what the greatest difference has there been between 2 fighters that have fought at one point of time (in any organization) and then later on gone in totally different directions with their weight - within the UFC organization?

So Penn will fight at featherweight and Machida fought at HW (around 230+ pounds it seems from what I have read).

Rumble might have some record?

I am also talking about fighters that fought in the Zuffa era - Keith Hackney and Emmanuel Yarborough don´t count.

Edit: Penn´s lowest and Machida´s highest are almost at 100 lbs of difference