Z Heads, 915 casting, 10139 date code?

.........The 360 head 1st came out 4 the 1970 model year.....915 casting........they had 2.02 intakes and 1.60 exhausts.......4 1971 they came with 2.02s 4 the 340s same as 1970, but the new 360 motor [4 1971 model year] only got 1.88 intakes with the same 1.60 exhaust valve..1972 up got the 1.88s...kim.....