Picked up a bunch of stuff today from an estate and one of the planes had this engine on it. I know it's a Saito and I think maybe a 180?The label has fallen off. It was on a Great Planes Super Stearman. I've got a 120 and a 150 but this appears bigger in size. Another thing throwing me is the black case but silver rocker covers. Never seen that combination . It is new and I've looked through all the boxes for a manual for it with no luck. Also no muffler. Is there another way to determine short of tearing it apart? Any help would be appreciated!

Saito Black Knight, most had Gold valve covers which could have been changed. Most likely a 180 or it could have been a 220. The Black Knights were available in several sizes.

You might try a post on Rc Groups, its for nitro and electric planes smaller than ours.
https://www.rcgroups.com/forums/index.php

The Saito Golden Knights were sized from the 30 up to the 220. Im almost certain that the 220 was a different cylinderthan the 120-180 models....

It could also be a plain Saito 220, with the case of the engine painted.