just rebuilt the su's on my 72
when the car is warmed up she goes like a son of a gun
my problem is that when the engine is cold she's hard to start
seems like the engine is getting no fuel
Double check the choke function and make sure the nozzles are dropping when you choke it. If you have disconnected the carb pre-heat line (coolant circulating through the bottom of carb base) that will contribute to some cold stumble without the choke until it is fully warmed up.