[Chevelle-List] Motor I.D. Help

[ECamino67]

I saw a 78 Vette for sale today with a 350 (I think)
  On the back drivers side of the motor it was stamped "Hecho en Mexico " ser # 10C66086 ............might have been 10036086,  It was hard to read , anyway , is there any way to find out what year and what size this motor is , I'm sure it is not original
          Thanks Much
             Jim  67 El Camino
                     78 Corvette