I realize I’m going to get a ton of different answers with this one, but im looking for some suggestions on what type of carb to go with. Engine is a 440, 10:1 compression with a voodoo 703 cam. It has TTI headers, a performer intake, 727 transmission and 355 gears. It has a reman Quadrajet on it right now and im tired of messing with it trying to get it idling smoothly. I’m leaning towards Holly or quick fuel, definitely something with vacuum secondaries. Any help pointing out the pros or cons of different carbs or what CFM size I need would be appreciated.
From Lunati
10230703 60303 1800 - 6200 .494"/.513" 226/234 271/279 110/106 Hyd/Hyd
This high performance street cam likes
2400 RPM stall, 800 CFM carb,
dual plane intake and headers. Makes un-equaled power to 6200 RPM with proper valve springs.
Is your Q-jet 750cfm or 800cfm? Stall? A/F ratio?
Many, many years ago when I went from being a straight line enthusiast to being an off-road desert enthusiast, I had a built K5 Blazer with a sbc 406, camelback 2.02 heads, 11:1 @4500ft, Lunati .230/.230 109/107 @0.50--cam tech recommended, Performer intake, headers, TCI 11" converter and a TCI TH350 trans w/3.06 1st gear, 3.73/33"
et al and an 800cfm Q-jet that was set-up by a SNORE member for off-road/highway and altitude, the Q-jet became a superb performer and worth the money after being worked on by an off-road racer (SNORE guy).
In typical Ford vs Chevy fashion, another member of our group was running an F250, 429ci w/B&M 10" converter, 4.56/35", Isky cam and Holley double pumper. Between the converter, weight of p/u and Holley DP, it was assumed by others and myself that his choice of cam was too small, and the DP was a poor choice because it bogged WOT. He was a co-driver for me on a short course, and I was going to be the co-driver for him, but, he didn't run his big block 429 that day.
My point in sharing this is, a much smaller 406 engine with a big, re-calibrated 800cfm carb outperformed a big block 429, it was the total package; ignition, carb, intake, heads and headers, matching weight and gear ratios. I have an Edelbrock 1407 carb (750cfm) that ran well at sea level, it needs to be leaned out (recalibrated) a bit for A/F at 4500ft altitude (less air to mix). In order to get the proper A/F ratio, the same would have to be done with a Holley, TQ, Q-jet
et al.
IMO, the simple solution is to take the Q-jet to a professional Q-jet carb person, it can be recalibrated for your goals. If a Q-jet can be recalibrated to take on the rigors of high-spirited, rough riding, bouncing desert driving at speed, it can be made to idle.
