it shouldnt be shaking at stoplights. i think once you get your distributor timing set how it should be, you will be fine. no need to swap camshafts to fine tune the beast. try 8* initial 35* total. make sure the vacuum lines are where they should be, pcv in front usually brakes in back any unused should absolutely be plugged. which carb???, we'll try to get you a diagram. shaking at idle could just be a vacuum leak. i have not followed the whole thread, but if someone wants to suggest a different standard timing let him know. it sounds like it's way retarded or advanced right now. or vacuum leak.