I few months ago I bought a used 480 with a build date of 9-13-14 that had the upgraded controller with high flow burn grate and ceramic igniter.
Just a couple days ago I bought a 640 with a build date of 5-1-13 that does not have the upgrades. I plan on selling the 480 but was wondering is I can swap out the controllers before I sell it so I have the upgrades in the 640 and then sell the 480 without the upgrades. Assuming it's possible how much trouble would the swap be?