Thanks Bill,

I'm glad to now know it's a 350 but I still wonder what it came out of.
That first set of numbers C5A146997 seems like according to the Z28 site a partial vin.

http://www.nastyz28.com/chevy-engine-code-stampings.php#suffix

I kept looking around, even saw this chart on the LMC catalog
http://www.lmctruck.com/icatalog/CBE/full.aspx?Page=9

but I still couldnt piece together what year/model this 350 is from.
Its not that important I suppose, just curious.