Call me a cheapskate if you want, but 500 is too high unless it has a money back guarantee, if cracks are found when Magged.
I bought last year, 3 engines, all with money back guarantee. All had severe cracks when tested that were unseen with the naked eye. All were returned.
I got a good one from Vern Tardell before he left for Texas. It was perfect for the same 500 bucks