Why not a 413 ?

I hear ya but only if you have money for a stroker.
I think I paid $1,400 for my stroker kit for my small block.. if I was going big block I would already have the $2300 in the budget... And a $500 block prep..
Think about what the Op has and what he's trying to accomplish...
no doubt in the end it would blow his budget but definitely get the time he's looking for..