This is the seven main bearing 200ci six-cylinder block. Most 200 blocks are seven main bearing, with the exception of its first year, 1963, where 200ci sixes had the 144/170ci four main bearing block. Ford redesigned the lightweight sixes to seven main bearings to reduce noise, vibration, and harshness. Four main bearing blocks can be identified by three freeze plugs. The seven main bearing block has five.