aluminum heads number inside of heads are 10207848 and another one that is 4164. front of the heads have two option were u can bolt the header. if that helps

 

You sure that first number's not 10207643?? As for the second one, not sure..
This is where i'm looking. Take a look.. http://www.mortec.com/castnum.htm
What did these come off of??

 

found them are they any thing speachile? well i guess it dose not matter because i had work done on them by LE

10207643...94-96...350..........Gen.II LT1, aluminum, reverse
flow cooling, 175/68cc port volumes