In my opinion, when you start a hot carbureted engine, push the accelerator half way down and hold it there (don't pump it!). Then engage the starter. When the engine fires and begins to rev up, release the accelerator. If the engine was flooded, you might have to wait a few seconds before it starts to rev up, and then release the accelerator slowly.

The procedure is also desciebed in the owners manual (sorry for the ads on this page, but you should be able to read the important bits): https://oldcarmanualproject.com/manuals/Pontiac/1969/Owners/pages/69PontOwnrManP05_jpg.htm