Every BBC Chevy head I mess with I always have to fill in these holes in the head for the manifold choke. These are off a Gen v motor. When was the last time Chevy used a manifold mounted choke to even need them?

Those holes are not for the "manifold choke" they are an exhaust crossover passage that is used to heat the underside of the maniold to help fuel atomization in very cold weather. It allows for decent driveability when the engine is cold. They probably have not been needed since GM stopped using carburetors but they are not going to change the head castings now. Also, most heads are used on cars and trucks, which still need the passage on older vehicles. By the way, filling them the way you are doing would not be my first choice. I would be real worried about the epoxy getting burned out by the exhaust gasses. Racers actually use melted aluminum to fill the passages, but for a street or marine engine all you need to do is cut a small piece of sheet metal to put over the passage and let the intake manifold gasket hold it in place.

Bill Koustenis
Advanced Automotive Machine
Waldorf Md

Thanks Bill.
I've been doing it that way (fill with tinfoil and the last 3/8th filled with JB Weld) for the last decade. Never had an issue with it.

Seems to me I bought intake gaskets before which included metal plates which fit into the gaskets to cover those holes.

Yes, I have bought intake sets that come with a couple different metal inserts. You can not use them and leave it open, use one which has a small hole that only lets a small amount of exhaust through or use the solid insert that totally blocks it. I think most Fel-pro intake sets come with these....I could be wrong

No, your right. Their Felpro. Just looked in my box of extra gaskets. Got a bunch with the small holes. Used all the solid ones.

I guess i need to check my gaskets. Seems like in the past this area was left open. I've been using Endelbrock gaskets for aluminum intakes.