Mods for 7.3 Excursion??

OK, so on a somewhat related note, when I was getting my airbags installed the other day at 4 wheel parts, I was talking to the counter guy about all this. He recommended not using a tuner, because of the age and mileage of the motor. He did think a gauge to monitor EGT was a good idea, but recommended a analog (dial) gauge, and said the digital ones are not accurate. I didn't call him out because I'm far from expert, but I've been messing with cars all my life. In my mind, the gauge accuracy is dependent on the info received from the sending unit, and the method of display shouldn't make any difference, except to the point where a "bar graph" type display cannot show RPM as accurate as a sweep needle because of the steps involved in the bar, but otherwise this seemed like someone who doesn't know what they are talking about. Thoughts???

BTW, I wanted to ask him if he gets better TV shows on a flat screen than on an tube TV. But I sorta figured I'd be wasting my breath.