408 crank?

Forced induction changes things a bunch. If it were naturally aspirated 550 hp or less I'd say you'd be ok but I wouldn't even think of using a cast crank for what your doing. JMHO

BTW: As far as Eagle cranks being defective, I heard that too after buying one so I had my machinist check mine over real good and he said it is fine. He magnafluxed it, checked it for indexing, checked for straightness, and checked the journal sizes. No problem at all. All it takes a 2 or 3 with a problem and it's spread like wildfire and everybody gets worried (like I did). For what it's worth he said he hasn't had one bad Eagle crank.