Need to know the name of this

Buddy's kid misplaced it some place and without i cant finish my coli

Its a camshaft cover or camshaft cap.(depending on who you ask)
The problem is, usually they are fit to size. Im sure you can just pick one up but you need to verify the clearance.
Too little and it will gall/seize up, too much and it wont hold the cam in place properly.
But, this isnt a racing engine so, Im sure it would work right out of the package.

Camshaft Bearing Cover/Cap