Air Cleaner assembly question

[mjm0103]

My son purchased a 1969 C10 pickup a few months back. It runs great so we're just tinkering with it to clean it up.

I thought I'd check the THERMAC out to see if it's operating because the truck idles rough for a minute or so when it's first started in the morning. I appears I'll need to replace either the sensor or the vent since the flap doesn't close off the snorkel on a cold morning like it should. But while checking it out I noticed that the Air Cleaner Assembly has a series of 1/4" holes drilled about 3" apart all the way around the perimeter of the assembly. The assembly also looks like it's been hand painted black at some point since I can still see the brush strokes in the paint.

I'm wondering if that assembly might be an aftermarket assembly and the holes were factory drilled or if the previous owner may have put the holes in himself.

Does anyone know if those holes are supposed to be there? I've never seen an assembly with holes like that before.

Any idea's?

[Aarons72s]

Pics would help. Mine didnt have the holes. As for the flapper. Most have long since been disconected and abandoned. Just let the truck warm up for a minute and go.