On the 9:1 306 with Trick Flow heads I mentioned above, I started out with a 650 double-pumper, on the suggestion of my engine builder. As others have suggested, heís a drag race guy.....enough said.
I was never happy with the way it behaved in the real world, even in a VERY light car (2,000 lbs) and a manual trans.
Iíve since switched to a 570 Street Avenger, vacuum secondary, and while I canít say itís the PERFECT carb for my application, Iím much happier than I was with the double pump.
As someone else said, be honest with yourself about what youíre going to be doing with this car.
I have been experimenting with different carb calculators and as you stated the 570cfm is what seems to be a good place to be since I'm not planning on spinning over 6000 rpms. The reason I went with the AFR 165's is because of how well they flow under .500. My cam Lunati 218/218 rpm range is 1800-5800, with the 1.7 rockers it gives me a little more lift so I'm thinking that the redline of the cam has shifted to at least 6000 rpms. With 10:1 compression ratio I'm thinking that I have plenty of power through the mid-range and top end. This is a C4 setup with a GV overdrive and 3.55:1 traction lock differential gears. 2400 stall converter
It will be used on the street and for spirited driving, but will never see a 1/4 mile strip or road course. Been there done that with my other vehicles and bikes. I just wanted a hopped up stang with 350-400hp.
18' Tesla P3
Previous fun toys
01' Twin Turbo Z06, 850 whp
06' CTS V LPE 427, 800 whp
09' Vmax, Guru mod 240hp
65' and 95' Mustang GT
87' IROC and 2000 Camaro
91' Firebird Formula 350