numbers for 455

hi there, just got a 455 and wondering if someone can help me out in what year it is...the numbers are as follows..

Block-1241735
Head-1246322
ex manifold-81238094-2
crank-1379242
intake-18436672

thanks for the help

 

Here's a resource for (some of) this:

http://www.atlantabuick.com/CastingNumbers.htm

It looks like a 72-74 block and a 75-76 head.

 

Perhaps a 1975.