Carburetor cfm calculator
Rustyratrod thinks the same as I. If your just cruising around, that would be a fine cfm amount. I’m running a Edelbrock 600 on 2 different 360’s right now. One is a 5.9 with bolt on parts only. Just a cruiser. It does see WOT every now and again. But it mostly is just driven here and there.
The other 360 is in the wife’s car and it is seriously under carbed. It does need another 150 cfm (750) for getting all the power even though she mostly just drives it. Her car is a high compression aluminum headed hot rod with a small ish cam @ 224@050 on the intake.
You can feel the limitation on her engine. (At WOT on the big end) While the carb will be changed out later, it’s still a good driver with excellent throttle response. Sometimes the smaller primary is a restriction that can be felt. I experienced this with a TQ on a dead stock (‘78) 400 with only headers and a intake change. I had at my disposal 2 TQ carbs. An electric choke small version was used first. Then I switched it to a early year big primary unit. There was a big difference in the power return with no mileage loss.
This is why you’ll see a 750 on top a 360 instead of a 600/650. A lot has to do with the rest of the build as well. Things that give way to a larger carb are things like increase cam, stall & gear.
See if you can get both size carbs as a loaner from a friend and try them out. Then you can decide which is best for you. Even though you didn’t list any parts for what a mild 360 is, a 600 would not be a bad choice. A larger carb will probably deliver more power up top, BUT! a lot is how often you will be there and do you need that last 10 hp?
IMO, the reason those calculators don't work is two fold. First, none of them take into consideration anything to do with what the combination is. Secondly and this might be the bigger one, they also don't take into consideration WHAT KIND of carburetor.
You know as well as I do an 850 AIN'T an 850. Case and point. An 850 DP Holley compared to an 850 Thermoquad.
An 850 Thermoquad can be tuned to run on a hot slant 6. That same carburetor can also be tuned to run on a hot 440.
Conversely, the 850 DP Holley will be way too much for an slant 6, while can haul the mail on a 440.
This is one reason the factories used carburetors like the Thermoquad and the Quadrajet. They are basically the same carburetors in a different body. Now all the Mopar chest thumpers will come out in force to disagree, but they're wrong. lol
They are both hybrids. Mechanical secondary carburetors with an air valve controlling the secondary barrels. They can be used on MANY different engine sizes from 318 to 440 with very little tuning differences.
As such, those calculators don't count for much when using that style carburetor. The Carter AFB and AVS and the new little Street Demons fall into the same category. They are all variable CFM up to their maximum through secondary door adjustments. Even vacuum secondary Holleys are similar with their changeable secondary springs and or adjustable secondary diaphragms. It's just hard for a calculator to accurately pinpoint, since it does not know your combination or what style carburetor.
If any of that made sense. lol
