Advice on a 625 CFM STREET DEMON CARBURETOR for 273 commando

I have had good luck with a 625 on an 318, when I changed the motor to a 360 it is still on there, starts easy every time hot or cold, pulls good, I would buy another one if I needed it. I got the one with the phenolic body, to cure heat issues in the summer, and it will start first crank when 0 degrees outside.
thats great. in arkansas so that will def. help. the motors pretty stout, but my brother built it for more top end then cruise. there is an 850 on it it takes it and asks for more, but low end it seems to stumble. its a rare card from holley ment for 427-454, i want something more lower end and not so troublesome. thats why i was looking at the street demon over another classic holley or edelebrock, am i thinking right?