Well I looked at the number again after I cleaned it off better with a wire wheel and sure enough it reads 460777 which is a 1976-1979 305. Now I'm just trying to figure out why somebody would go through the hassle of making this motor from a 1976-1979 to a 87-90 motor, because all the other ID numbers from the water pump, intake and, exhaust point to a 1987-1990 305 or 350. Puzzled and very stumped here. Guess the only other thing to do now is yank the oil pan and see whether we got a 2 or 4 bolt here. Any other suggestions guys?