I jsut bought a formula with 525sc's
because they are very reliable, blown motors
I plan to maintain them to death and keep them for a very long time.
I am unaware of any 525sc's that had any problems beyond possibly a value train spring issues that a similar cam'd 500hp might have had
seems when someone starts to tweak beyond a reliable scenario to get more power, they then run into problems
take my nitrous injected snowmobile engine for example
( don't ask)