z28 intake ouestions

[Peter D]

1969 z-28 question #1. waterneck lower driver side corner has a thin triangle cast into it with a 1/16 (approximantly) inch hole. Is this a stock water neck or something oddball? If it is stock, what is the hole for? #2 the intake manifold (same car) has a 1 1/4 freeze plug in the place where earlier (pre-smog)manifolds had a riser to add oil. Is this manifold period correct or a bogie? As always thanks in advance. Dazed and confuesed [img]/ubbthreads/images/graemlins/confused.gif[/img] [img]/ubbthreads/images/graemlins/confused.gif[/img] [img]/ubbthreads/images/graemlins/confused.gif[/img] [img]/ubbthreads/images/graemlins/dunno.gif[/img] [img]/ubbthreads/images/graemlins/[/img]