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Gents,
It's been so long since I've driven a truck with a carburetor. I'm not sure how it works best. Before efi we used to pump the pedal and crank it. I've got a 216 with a Rochester one barrel. Don't have either throttle or choke manual cables hooked up. Yet.

What's your starting sequence?

Thanks Don

1 pump of gas pedal.
Max choke ( you'll need to reconnect your choke cable)
1/2 open throttle. (you'll either need to reconnect your throttle cable or hold it with your foot).

On my 49 once it starts I push the choke fully open then slow the fast idle down to around 1000 rpm to warm up.
Driveability right after start depends upon a lot of factors, I usually warm up for a couple minutes.
Good luck

I give the gas pedal about 3 good pumps, pull the choke all the way out and start without touching the pedal. it fires right off for me.
then I give it a few seconds and push the choke cable back in.

With the choke working properly and a clean carb, it should not be necessary to pump the throttle. Hold the pedal slightly open, pull the choke knob out all the way, and crank the engine until it fires. Push the choke knob in partway to avoid flooding and let the fast idle cam attached to the choke linkage increase the idle speed. Within a minute or so the engine should warm up enough to open the choke all the way.
Jerry

Can anyone explain what actually happens when we pump the gas pedal to start?

Thanks Don

The accelerator pump squirts a couple of streams of raw gas into the intake manifold, where, hopefully, it evaporates enough before it gets to the cylinders to keep from wetting the spark plugs and flooding the engine. Pulling the choke knob all the way out allows intake manifold vacuum to go all the way to the top of the air horn and draw gasoline through all the passages in the carburetor, creating a rich enough mixture that the cold engine has a better chance of starting.

More sophisticated carbs like the Weber DCOE series have a small-diameter "starting enrichment" venturi that is opened up by a cable for cold starting, and no choke plates. There's a fast enough airflow through the small venturi to provide a richer mixture for cold starts.
Jerry

I never touch the accelerator when starting my truck, even if it's set for two or three days. I simply pull the choke out and hit the starter. She always starts in less than one revolution. If I pump the gas, even once, I'll flood it. This is a Rochester on a '49 216.

My 235 is like twotone's, just pull the choke out an inch or so and she fires right up. When I first got the truck I would pump the accelerator a time or two, and it would take several attempts before it would start. You will just have to experiment and see what your truck likes.

This is what I have also found to be true.

My Suburban starts first-time, every-time, even if it sits for 3-4 months over the winter.
It now has a 1960 261 and one Holley AA1 carburetor.
The starting sequence was almost the same (but was a smoother start) with the original Rochester.

My starting sequence is:
- push accelerator/gas pedal to the floor and release - one time
- set the choke at about 1/3 out
- pull the throttle just a little
- push the starter foot-pedal
- when it catches, push the gas pedal a little and push in the choke

I am looking forward to seeing how the 235 on my 54 Hydra-Matic starts - it has the stock/original Rochester BC (auto-choke) carburetor.
It started fine for the engine break-in.