mumbling n grumbling at a stop light

before you even take the air cleaner off that carb you need to get the timing squared away. that is the FIRST step to tuning. the timing events directly effect the air/fuel. find out what your initial timing is with the car idling in gear (parking brake set). then find out what your timing is at in park or neutral at about 3500 rpm. have a buddy sit in the car and get your timing light out. have him/her very gradually bring the rpm up until you see the timing stop advancing. my guess is that you have very little initial timing and it is coming in way too late. I am no pro here but i have got alot of help with this exact topic from members here and i have been reading a ton. what i think you need is about 15-18* of initial timing and a total of about 34-36* BTDC (before top dead center) and it should be all in by about 2800-3000 rpm. this is more then likely gonna require a recurve on your dizzy.