I am using a Holley 1850 600cfm on my 318. The only tinkering I have had to do involves jetting it for altitude and with the new blue gaskets it is a breeze. Either carb will work well once it is set up. Both carbs don't like too much fuel pressure.
I am going to try out a 570 Street Avenger, I like it better because it has two metering blocks so you can change jets in primary and secondary bowls. The 1850 has a front block and rear plate, although there are kits to use jets in the back.

R.