Here are the 351-Cleveland engine variants (all from 1969-1974):
1969 - Boss 302 (Technically a Windsor)
1970-1971 - Boss 302 (for half a year), 351-4bbl, 351-2bbl, Boss 351 (the best), 351-CJ (CobraJet), 351-2bbl Aussie, and 302-2bbl Cleveland (Australia only)
1972-1974 - 351-Cleveland HO (High Output), 351-CJ (CobraJet) -- these two were the only 4bbl Clevelands -- 351-2bbl, and I think they made the 302 and 351 CLeveland Aussies (Australian) until '73
From 1972 onward, the 351-CJ was the preferred Cleveland engine in the states. In 1970-1971, the Boss 351 ruled!