Cylinder Identification Help Please

[mastaphixa]

I have been toting this cylinder head around for years and never have figured out what engine it is from. It's a bit odd as it has the intake and exhaust and intake manifolds on opposite sides of the head. I always assumed it was from a radial of some kind but after looking at pictures of everything from a R985 to a R4360 I can't seem to make sense of it. I'm sure someone will recognize it straight away.
Thank you,
Steve

Attachments

[Cvairwerks]

R-2600 maybe?

[F3A-1]

Possibly 1820, but it is a Curtiss Wright.

[mike furline]

R-3350-57, cylinder bolt pattern, 5 holes, space, 5 holes, etc., staggered intake/exhaust tubes.

https://www.flickr.com/photos/13877445@N06/9169102475
https://commons.wikimedia.org/wiki/File ... Engine.jpg

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[mastaphixa]

Thank you Mike Furline!