Adam,

It looks like you have a 58-63 block and a 54-55 head.

Would you please post your head date casting code?

You might want to also post a link to a photo of your connector. It could be the earlier style I posted above - which style of connector does it look like (1954 or 1959)?

If yours is like the one in 1954, I have seen almost all of these pinched a little at the outflow tube (perhaps to increase pressure a little?).