How close are your pots?

Is 3.25" Kettle to Kettle spacing too close? I've got an opportunity to use a really strong stand, and just add the top portion to it. If I can get away with this spacing I can really keep the design clean and compact.

I can't imagine that would be a problem. Keep it compact!

I have 2, 20 G Blichmanns on a 4ft. stainless table, resting on 2 Blichmann burners, with 11.5 inches of space between the kettles. I did this, only, to keep the weight of full kettles closer to the legs on each side of the table. When the water boiler is fired at full bore. The side of the wort boiler, closest to the water boiler burner, gets fairly hot. The wort kettle is empty, when I'm heating 18 G of water. With my set up and process, it doesn't pose a problem. If you are using gas, the heat off the burner may effect the other kettle, with your 3.25 dimension. That may not be a problem. It may pose a problem if one of the kettles is a mashtun. It depends on your set up and brewing process. I would have used a 3ft. table; better feng shui. But, I had a 4ft. wall space to fill.

One vessel is going to be the mash kettle, and the 2nd the boil kettle. The only time I can think of that it could be an issue would be if doing back to back batches. During sparge there may be a bit of carryover, but at that point it should not be an issue I wouldn't think.