Need some help on a 1966 K19 Holley 3605 Carburetor

[Robert T.]

I'm trying to decide what the rear bowl of a 66 K19 car with a List 3605 carb should look like. When looking at the rear of the carb, I've seen some with an approx 3/8 inch boss drilled out in the lower left corner, and some without. Can someone please tell me what is correct for original.

Thanks in advance for any help you can offer.

bob

[Robert T.]

Re: Need some help on a 1966 K19 Holley 3605 Carburetor

If it helps any, here are a couple of pictures of "original" carbs dated one week apart. One with the boss, and one without. Looking at some other types of carbs, I see this same variation, i.e. some with it and some without. Was this just a permissible variation? Don't know what it is even used for. Thanks again for any help
with boss.jpg no boss.jpg