[Hammer]

Under normal NA conditions, most bolt-ons will not effect the engine dynamics enough to warrant a different program, which is why you don't need a chip after purchasing a cold air kit or new MAF. In that respect the tech is correct...

But, I know of no "smart" program in a stock PCM that will "sense" whether you have 3.55 or 3.73 gears...

If the PCM is flashed for 3.55s and you go with 3.73s, if you want the speedo correct the PCM will need to be re-flashed or an aftermarket chip added, as a speed cal will not work with 99 and up autos....

There are after-market chips\PCMs that let you do your own re-flashes, but this is not the case... Steeda does the flash in-house.

My honest opinion is to buy a standard chip for your current setup, but one that can also be flashed at a later date with a custom dyno tune.

Find a local shop in your area that dyno-tunes and see what hardware they use. Buy the chip with a "standard" flash for your current mods, and if you ever decide on a dyno-tune, all you'll need is the cash.