Engine Surge While Stopping

if this were me the first thing i would do get my hands on a known good running carb to rule out the carb alltogether. it is much easier than trouble shooting a carb coupled with all the other problems you may have. i have been in your shoes with all the symptoms and the carb was the problem the entire time
#1 retorque your intake bolts at 35 foot pounds
#2 make sure your points are clean and gapped correctly. if it were me, i would ditch them all together and buy an electronic conversion kit or as others would recommend a GM HEI conversion.
#3 with the advance hooked up, dial in your timing at 32* total at around 2500 -3000 rpm.
#4 back to the carb, take it off , set the floats, clean it out, make sure nothing is binding and that the primary and secondary butterflies are working and obtaining WOT fluidly before you bolt it back down. this literally takes 30 minutes. check for any gasket obstruction before tightening it down
#5 fuel pressure, you need 5 to 5.5 for that carb
#6 vacuum leaks/choke

one or more of these are your problem. also and again, run the car without the vacuum advance and the choke tied open to make sure it isnt vapor locking or the advance plate is sticking