Ford Lehman Pushers should get on this
That's the FL135. Somewhat different beast than the FL120 (it's based on the Dover engine, the FL120 is based on the Dorset engine). But a lot of boats used the FL135 clear up into (I'm pretty sure) the 1980s. It would be interesting to know if this particular engine has the full Lehman Bros. marinization kit on it and that the components are in good shape.
If it does, it's a hell of deal.