Sizing carburetor
I’m building a 360 stock stroke bored .030 over, flat top pistons says would be 10:5:1 compression, ported X heads, Schneider cam 480/430 220/210 at .050, eldelbrock rpm air gap intake, Doug’s long tube headers. It will be street driven only but I’m not an easy driver. Coan torque conver 2500 stall, 904 trans with reverse manual valve body. All redone with cope racing internals, 8.75 posi rear with 3:23 gears. Online calculators say 689 cfm.
So what I *think* you are trying to tell us is that you are looking for a carb that will be pretty close out of the box.
* You will not be taking it to the track or a dyno to tune in the full load WOT.
* You will use it at least three seasons of the year.
* Tuning will be somewhat limited.
With those goals, the rest becomes easier. Carb with choke tower. Automatic choke if it has a pull-off will be a plus. You call on whether choke (auto or manual) is important to you).
Carb that is decently calibrated as purchased and doesn't have known issues (like the Eddy 750 and many of the newer Holley 4150 types with excess emulsion etc)
Smaller primary venturis will be easier to dial in than larger ones.
A secondary that is actuated by demand can be a benefit in this situation.
Go with the carb system you think you'll be most comfortable tuning. Off-idle is the most difficult to adjust if it can't be corrected with throttle-transfer slot rlationship. The Carter low speed circuit is more sophisticated, but if a Holley type is off - its more accessible if you are willing to put in the time and effort. These are the trade offs. High speed and full power is jets and rods/springs or jets and power valve restrictions/PV.
Nothing will be entirely plug and chug - just some will require only the basics: Timing, Fuel level, throttle position, idle trim. Then adjust high speed cruise restriction, and wide open throttle - full load as much or as little as you want.
