What are these intake manifold tubes?
 

1974 F100 460

And do I need them? One I think is the old hot air choke and one goes hooks to the carb via a vacuum line. As you can see the carb has an electric choke and (what I think it is) the old hot air choke tube attached to the choke.

Could I eliminate these and is there a block off plate that could replace the plate with the two holes in the intake manifold.

What does the line that goes to the carb vacuum port do?


http://i278.photobucket.com/albums/k...g?t=1385168586

http://i278.photobucket.com/albums/k...g?t=1385168658

That's a choke heat tube...AKA hot air choke tube.

Are you subject to emissions testing?

No emissions testing required in my state due to age.

What is the second tube beside the hot air choke that has the vacuum line to the top of the carb?

On the stock setup, one tube ran up to the top of the carb and sucked in fresh air while the other ran through the choke cap and ultimately accessed a small vacuum port. Air was pulled from the top of the carb, down into the manifold where it heated up, into the choke cap where it heated a bimetal spring, and then ran through a small hole in the carb which sourced manifold vacuum for air flow.

So I could eliminate them now? Is there a block off plate of some sort?

Yeah, you don't need it with that Holley choke. There aren't any block off plates that I'm aware of, though it wouldn't be hard to make one of your own.

Maybe pull the tubes out and put a couple of screws in the two holes of the current plate.

Please refer to the following thread:

https://www.ford-trucks.com/forums/8...-answered.html