Quick question for all of you, obviously from the GMC emblem cast on my valve cover my motor is a GMC, the question is which one. The engine number on the vin plate (on the driver door) is G35965. The casted number on the engine block driver side in the midle of the block : 6107328, still on the driver side but totally on the left writhed upside-down: 6743, again on the driver side in the middle, in small print : J73. According to this site: 3W.adchevy.com/tools/castinglookup/?castingnumber=6107328&submit=Lookup# it would be a 248 1953. Is this information reliable?