you forgot the 396, which is also a bigblock. The 400ci is a small block high torque long stroke engine mainly found in trucks. you can also stroke a small block to 427ci....the differencein ford big blocks & chev big blocks it that the Ford crank is externaly ballanced (add weight to the crank rather than remove the weight from the heavier side) you just get better life from bb Chev & less wear on main internals, plenty of BB ford cheap!