7019927 is used for the 1961-65 M/T center carb.
7011997 is used for the 1959-63 outer carbs.
Your center carbs #2 and #4 looks like genuine Pontiac Tri-Power units.
#4 for 1965 M/T, #2 for 1961-64 both A/T and M/T.
Check this out (thanks Jon at "thecarburetorshop"):
https://www.thecarburetorshop.com/Tripowerspecs.htm