I drive EVERY day, i hate cars that collect dust in the garage, thats why i went 331, from what i hear it has better reliability if it's true or not i will never know.
Yes, technically it is true. It has a slightly less steep rod ratio. The lower the rod ratio, the more 'sidewall loading'. That equals more friction.
Proof: http://www.fordmuscle.com/archives/2003/09/stroker/index2.php
If I was a betting man, and could create an experiment for 150,000 miles I would pick the 331 over the 347 to show a bit less sign of wear.
If you go 347 (not much more power than a 331) just get the 5.315" rod, again to keep the wrist pin out of the oil ring. You'll thank me 50k down the road
A bit over a year ago I tore down my engine and had a basic rebuild done, if I had would have extra money to get the balancer, flywheel, stroker rotating assembly, and custom cam, I would have went with a 347 with the 5.315" rod, just so you know. It was a daily driver then too...