i have the valve covers that were on the engine my friend put new ones on it for me but i wasn't there so i couldn't look for the casting number
to my naked untrained eyes it seems that the block and heads are the same age the paint or what is left of it seems pretty much the same everywhere the valve covers aren't finned aluminum but could also be a choice by the guy ou replaced the engine the heads may not be the originals but would it mean that they had to redo the heads to fit the engine can regular 350 or 305 heads with the lifters etc... fit on a 350 lt1 from a camaro