I second this. My reason is that as the engine heats up, the metal expands ever so slightly.
FYI, a 100 foot piece of steel heated up to some temp (I cant remember)will lengthen by a foot.
The slight increase in gap will do exactly as cbrider said. It will make the whole train last longer.
you might notice a slight increase in noise so be prepared for that. You might notice it.
I do this same thing on my 78k. I increase each gap by .001 and it does seem to help slightly with power but then that is coming from the butt dyno.
The ride IS the adventure. The destination is just to get gas!