casting #'s question?

[chevythunder]

Ok so heres a question for ya does anybody have a clue about the casting numbers on chevy 305 heads. I have to sets of heads sitting in the shop and when i run the #'s thru the books i come up with nuttin. i was going to use a set of 305 heads on a 350 project for propane operation to bring the compression up a bit to get a little more outta the propane, i know there wont be much more but i know a little more goes along way .The numbers on the first set are as follows (14102187) now the other set of heads will require shaving due to a slight bend in them so i hope that what i have here completely rebuilt are the 305's in question or i think im on a wild goose chase i think my books are so far out dated that i might be missing a page or two so if you have an idea i would really appreciate it thanks guy's