People have done every possible engine in a fox that can be done, including a cleveland. There are really cool swap headers out there that have 4 primaries coming into the collector side by side, flat against the floor.
A Cleveland has outlived it's glory days. When a Windsor was a dog because you had no head options,..the Cleveland was the obvious choice for power.
All that changed in 1990.
If I recall correctly,..a CJ was the weakest of the Cleveland offerings, smogged up, w/ low compression,.....not gonna set the world on fire by no stretch.
Q 351 CJ (much less common)
The May 1971 / - 1972 Q-code Version (351-Cobra Jet, 266 HP) was a low-compression 4V variant employing a cast-iron intake manifold (with telltale spread-bore carburetor flange), special camshaft, hydraulic lifters, dual-point distributor, 4-bolt main caps. A small number of late 1971 351C-4V engines were actually low-compression 351-CJ engines, and were equipped with an aluminum intake manifold.
Q 351 CJ (much less common)
The 1973 & 1974 Q-code Version (351-Cobra-Jet, 246 HP) was essentially the same as the 1972 351CJ though with two important differences: Camshaft timing was retarded by four degrees; cylinder heads- though still with large 4V ports - were fitted with smaller valves (2.04" Intake / 1.65" Exhaust), same as used in 351C-2V.