Ah, I get it. I will keep this in mind when I haul it off later in the year, but I don’t suspect this either. Although I know there is slack in the shaft bores, I don’t consider it problem enough as yet. I consider that problem solved for now with the installation of a manual choke a permanent solution.
I have Edelbrock Performer 650’s on two 350’s, and yes they are easy to set up and swap parts. I have a problem with both, but maybe I’ll start a new thread for that.
“It does seem to take an unusually long time to warm up. Could be my disemboweling the heat riser…”
Do you think they installed those exhaust control valves for no reason?? No wonder you have to reset the choke in the spring and fall. Have you found and unsealed the idle mixture screws?? Richened up the main jets a notch or two?? This is a smog motor. You can’t butcher the emissions control devices and expect this car to run right. They barely ran as it was…
The problem doesn’t always happen. Some will run fine without it. I think that the original setup would have kept the problem from happening. If you have too rich a choke adjustment, the engine will eventually foul the plugs and then won’t start. So, if that happens in the future, you’ll know what caused it and can correct it. For the other readers here, that pipe is important. The heated air was designed to be the only air that gets to the carburetor until the engine gets warm and after that it will allow about 40% of the air to be warm. That also improves the fuel economy. Many Chevy engines will try to stall without that pipe, especially those with the two barrel carburetors.