The original Boss 302 was not really a Cleveland engine. It was a Windsor with Cleveland style canted valves. 351 Cleveland heads took a lot of modification to fit on a Windsor. The 351s in the late 70s to early 80s F-series pickups are usually Cleveland motors and are not that rare. Check the junk yards and go for it. Actually a bored and stroked 351 Windsor can be brought up to 427 cu in with close to 600HP.
1989 Blue LX Hatchback
2001 Red SVT Cobra Convertible (Phoenix)
2002 Black/Red GT (Ginger)
2011 Red Candy Metallic V6 (Manfred)
2016 Magnetic Metallic GT (Susie II)