[undy]

I know of several 200k mile Chebby aluminum LS motors running around in C5s locally. One in particular has been dogged pretty hard too. Engine temperature management is much more critical on an aluminum engine due to the increased thermal growth issue. MFRs will target certain clearances by maintaining temps a bit more precisely. Methodical warm-ups are much more important too due to improper clearances at colder temps. Poor ring seating, cylinder wall scuffing and ultimately excessive ring blow-by are the primary occuring culprits of a routinely "beat on" cold/too hot aluminum block'd engine. You just need to be a bit more mindfull of what you're driving and keep a routine eye on a reliable temp gauge. An aftermarket aluminum FE block if properly maintained and driven should last every bit as long as the iron version.

I would put any stock in his "generalized" uninformed deduction...