Carb base gasket question - picture

Humor me here. :D
Lets assume there is no ignition problem with the engine, and that this stumble is related to a lean condition, commonly called "Lean Misfire". I want to install a thinner step rod, and/or a bigger primary jet, and perhaps a stronger step rod spring. Now, I know I can order this stuff from Summit and other places, but I have no idea what carb I have as none of the Edelbrock numbers listed on their site are even remotely close to what is listed on my carb. All I know about the carb is that it is a Carter Competition Series. I don't even know the CFM.

I replaced the open gasket with a 4 hole design that is almost 1/4" thick, and it made a HUGE improvement in the stumble, but I can still feel it a little while pulling a hill. My plugs are still colorless as well. I want to richen up the carb a little.

Can anyone tell me what to order as far as carb parts (rods/jets/springs) so I can richen up the carb? The numbers from the front baseplate of the carb are: 9636SA 0420.

Thanks for the help!!!

George