If your keeping your stock setup, in this case I am on my 67 GT 390 with the Holley 4v and automatic choke. Most systems being this old have a rusted and broken choke tube or in my case the tube was still intact but it didn’t take much of an effort to bent it and have it break and find the tube very thin. At this point you could dig out the end of the tube and just replace the tube which most people do. I was concerned of it being plugged up so I went a step further to replace the choke stove end cap fitting.
Plan A: would be to try some heat and vise grips to pull it out. I think you success rate would be less than 50% with this method and most likely end in frustration. I skipped plan A and moved to plan B.
Plan B: Drilling out the fitting to release the press fit. I found the fitting material to be soft and easy to drill. Having access to a mill made the job super easy but you could do the same with a small drill press. A vise and hand drill would be the last option but could be successful as well. I set it up on the mill to get it aligned and find to center the best I could. First drill was 5/16" to get a pilot hole. Then stepped up to a 1/2" to not get into the side wall of the exhaust manifold and see how close I was to the center. Found I hit the center perfect and with a pair of vise grips I could turn the fitting but not remove it. I then moved up a size to 9/16". That was the final step needed and it twist out very easy with the vise grips. I wouldn’t go bigger than 9/16" as you risk getting into the side wall of the manifold. If it didn’t twist right out at this point I would apply some heat and try it vs the next size bigger drill bit.
If this looks above your skill level. A machine shop could do it for you and the cost should be minimal. It took me about 20 minutes from setup to tear down to complete this task.
I got my parts from NPD as I was placing an order for other stuff as well. Most vendors should carry the parts. NPD Part#9C786 for the fitting and varoius different tube kits depending on your motor. 390 FE is 9819-2AS and is stainless steel made by Classic Tube.
I found the manifold mesh screen cleaner then expect but got peace of mind that this will help the choke function properly.
Jealous of that beautiful mill! They open up so many more options!
I would not have known how that fitting came out, Im sure this will help others down the road facing the same challenge.
Here is a link to a pdf file written by Bill Upham titled ‘Restoration “How 'to” Rebuilding the Exhaust Manifold Choke’ that shows how the air inlet tube and how to remove and install a new air inlet filter.
https://www.428cobrajet.org/sites/default/files/choke-stove-rebuild.pdf
Coach Jack