As with all Mustangs which come from Ford naturally aspirated, some will make it 50k miles with boost. Some will make it 20 miles. Just make sure you have a plan in place in case it does go boom .
And everybody else seems to think that it'll be the pistons.
On a side note, I am looking forward to eventually breaking the 11 second barrier but I'll have to work hard for that. I think I'll have to use a 125 shot too.
Only one way to find out...give it time for more people to boost their 281 3V and over time you'll start to see a limit of stock internals before they fail.
We put a Vortech H/O kit on a Roush, with 10 lbs of boost and a safe tune it made 450 rwhp and 400 rwtq. Guys been beating the s**t out of it for a month now with no problems yet!