[520CheyenneK10]

Originally Posted by Nothinghead

Here is where I got my info from on the suffix:
http://www.nastyz28.com/gm-chevy-cod...s-suffix-8.php

TKY 1974 350 160 4 conv.cab
TKY 1978 350 165 4 fwrd cab
TKY 1980 350 165 4 conv. cab, m/t

Great! Looks like my rig has the original block thanks to this web link. Thanks!!!! Also found this link which covers a larger range of Suffix codes: http://www.chevymania.com/partsid/su...fm?block=Small