What kind of engine does my ford have?

I have a 1978 Ford Ranchero how can I tell if it's a Cleveland or a windsor? All I know about the engine is its a 351m

She's a Cleveland mate

351 Windsor 5-bolt straight valve covers, radiator hose to the intake manifold regular 5/8" spark plugs.

351 Cleveland 8 bolt 2-plane valve covers, radiator hose does not connect to intake, small 14mm spark plugs.

The M is a 400 block with a 351 crankshaft and stoke.