rolling back of LS1 odometers a common practice?

i've been doing a LOT of carfax's on different cars lately and it seems that with quite a few LS1 cars the odometer readings appear to have been rolled back.

is this an easy practice to do? I AM NOT LOOKING FOR HOW TO DO IT, just if its possible and if its something i should be looking out for when i'm checking out cars.

is there any tell-tale signs of an LS1 being rolled back?

I think the only way to roll back the digital odometer is to access the computer. The dig. odo. is just a visual representation of the mileage stored in the computer. If the guy was good, there may be no tell-tale signs the computer was tampered with, other than a 100,000 mileish-looking car with 50,000 miles on it (if you know what I mean).

I know very little about how carfax records mileage, but I would imagine it is quite difficult to turn back a LS1 odometer. At the same time, I know of a 98 SS that is half V6 (rear) and half SS. Only telltale signs (its carfax would be clean... it was done all on the downlo) is that it is a M6 car with 3.23 gears. Well that and some very well done/hidden welds. Basically getting at carfax has only a slight clue as to what goes on in the history of a car. I mean, it takes miles reported from inspection stations, dealers etc.. all may not be transposed correctly.

Things to check for which would indicate high wear, but may not be thought of... sway bar end links... they wear very fast in these cars... mine were trash by about 25k... this would help you identify a 35000 mile car from a 10000 mile car. Dont know much about how to tell the higher mile cars apart.

There was a post a few months ago about being able to take out one of the fuses and the mileage wouldn't be recorded, but at the same time the gauges wouldn't work.