by megavega » Sat Apr 18, 2009 12:06 am
I wouldnt worry too much about the 4 bl on the v6, from your post , the carbs youll be using are all vac. secondary carbs, which means the engine opens the secondarys based on load applied via the engine, so if the engine cant open the secondarys all the way up,its not going to be over carbed or flowing 600cfm. So if the engine can only open the secondarys 3/4 the way up wide open, it might only be flowing say 450cfm, even though the carb is or can be opened to 600cfm. Thats whats nice with a vac. secondary carb for the street, you dont get that option/convienance with the dbl. pumpers, they will show you too much carb as soon as you smash the gas pedal.....bog....
Now granted a q-jet will be a little more responsive in the low end due to the small primary throttle blades and smaller venturi, the smaller the venturi/throttle blades the stronger the vac.signal is recieved by the carb/engine, thus improving throttle response. The smaller the venturi/throttle blades are the better the gas mpg,throttle response will be if thats what your after. Have you ever had a 2bl older v8? they had very crisp throttle response, got decent mileage, when you went to a square bore, 4 bl carb like a holley, you loose some of that for a gain in topend hp from the added airflow, because the venturi and throttle blades are now bigger then those of the small 2 bl carb(losing velocity from the larger diameter). Just comes down to what your doing with the car and what you want from it. pick your poison.
1972 hatchback, 28,000 orig miles, 427BBC/twin T4 turbo's/T56 six speed/big wheels, lowered down pro touring style-work in progress....
1973 vega wagon-under the blue flame knife.