I. D. heads

Hi guys, help me out here. I have a 1968 440 hp block. I also have the heads that I got with the motor but don't think there the originals. the numbers off the heads are,
rt side,
2843906-8
31
11017

LT SIDE,
2843906-4
31
10267
any help would be appreciated, I've had this motor in my basement for 25 years and just started decoding it. the block is out of an early 69 charger r/t.
thanks, Dan.