440 heads ID help

[bigowhiteboy]

I've been eyeballing a set of vintage rebuild heads locally but am having a hard time identifying them. The casting number is 2406520 or possibly 2406526. The guy thinks they are 65-66 440 heads closed chamber. Anyone seen this casting number before?

 

[Seax440Dodge]

probably 516's (2406516) which is a 64-67 361/383/413/426w head.... especially is the first 5 digits are for sure 24065... it's either a set of 516's or a set of max wedge heads (which would be 2406518)