agree 100% with dougie.

Basically, if you never, EVER detonate then yes, your 420a will last forever on stock pistons. But the HRC fuel system, with it's pushing-the-limits-just-to-get-the-bare-minimum specs plus the flaky components will almost guarantee you detonation.

I'd be willing to bet that most stock engines that aren't dead after several months of HRC turboing are simply not using the HRC-supplied cartech, FCD, or stock injectors.