The cross on the block means nothing at all, there is NO WAY of decerning any regular 440 block from any other 440 block, they all started as the same casting, period end of story. As each block was pulled and final machining was done "Notes" in the form of letters and symbols were stamped into the raised ID pad on the front drivers side of the block. One letter stamp indicated the model year car it went into (B=1966,C=1967, D=1968, E=1969, F=1970,G=1971) 440's assembled as "HP" engines were all maked "440 HP" and then some where marked with a "1" or a "2" which meant assembled on the first or second shift. So, an engine stamped "F 440 HP2" would be a 1970 High Performance 440 engine assembled on the second shift, this could have been either a regular 440 four barrel or a six pack engine. Only the VIN identification on the block (a machined pad down near the oil pan rail) could identify it for certain as to which engine it was, this would be reflected in the VIN sequence which indicated the cars engine designation (U or V code) or if the VIN on the car is known and matches the sequence on the block (often the VIN is incomplete on the blocks).
