318 with headers

Decided to try putting the headers on my 318. This is a late 70's/early 80's 318. Pulled the exhaust manifolds off and noticed tiny air injection holes under the exhaust ports. It doesn't look like the header flange will cover these. Whats the best way to delete these? Thanks in advance, Bob

Drill and tap the holes... put in allen head
pipe plugs

You can JBweld them.
Tap and set screw them.
Drive a nail a little larger size and trim it of.