Speaking from personal experience... I've got a 2009 5.7 (Eagle) Challenger that's had a Procharger D1SC @ 8 psi since July 2011 (installed when motor had 50K miles) and about a year and a half ago I bumped it to 9.5 psi. I also installed a 392 (6.4L) fuel pump before bumping up the boost.

I've got over 133K miles on the engine now, and haven't had the engine apart. Just general maintenance. And no methanol.

I've been to the track a lot with the car... since new I've had it down the 1/8 and 1/4 mile 531 times, with roughly 230 of those after the supercharger install. All supercharger runs where either on drag radials (early on) or slicks (later).