Wow nice find. That's a 1960 352 HP block. Ives is correct as the 6015 identifies the number as a block from a production vehicle. 6010 is the number used on over the counter bare blocks found on the box and block tag. The casting number on the heads is between the center two spark plugs. Date codes on the heads are above the casting number under the valve cover area. The block date code on a 60 block is above the oil filter adapter mount and is upside down. Both head and block date codes are a number/letter/number(s) sequence. The block date code will have a :1, :2 or :3 after it which was the shift the block was cast. Ex: 2 J 20 :3 . The first number of the date code is the year like 0 for 60, 1 for 61 etc...the letter is the month. A-M are the letters used skipping the letter I as it was confused with a 1. A =Jan, B= Feb and so on. The last number or numbers is the day of the month the block or head was cast. G.