4-barrel recommendations

[okie4570]

Call Jet Performance and give them you engine specs. They will build a carb specific for you needs. I’ve been running JP quadrajet for 12 years and have never touched it.

^^^^^^^both mine are from jet performance. Comes pretty much ready to go.

Make that three of us.

 

[Pa PITT]

... Being at the Parts Story for so many years . I'm going to say . That QJ JetP does sound the best ... But I'm a huge fan of the Edlebrook 600's ..
Now back when I had my parts store I got 2 bad AVS in a row . But I still think it a great street carb.........
............
.............But I don't truly consider the Bronco A street machine ... SO I think the QJ is the best because it will work on the Offsets of the rocks .. It'll almost run uphill .
My AVS, I LIKE, DOESN'T like anything except a flat strip. It has a great response but I don't think it like slopes & dips & Dives .

 

[Madgyver]

QJet here...........................

 

[Rustytruck]

Quadrajet stocker from a 350 chevy. using the 1964 to 1968 ford cast iron 4 barrel manifold and 1 inch adapter. fits under steel hood with factory air cleaner, down shift lever for the c-4 not used just wired up wit a spring to pull up on the lever at all times.

very important to keep good sealing gaskets between the carb and spacer and spacer to manifold. any vacuum leak under the carb and it will make the carb run rich as it effects the fuel transfer ports in the carb. rebuilt the carb 25 years ago when I put it in and other than replacing the base gaskets twice haven't touched the carb. use a fuel regulator and keep it under 4 psi. I use a cagle regulator that is no longer made. its a great offroad carb almost doubled my off road mileage when in 4wd. doesnt care about high altitude, low altitude off road bumps and nose up or nose down. it will change your life in an offroad rig.

 

[badandy73]

Ended up picking up an Edelbrock AVS2 650 from a local speed shop/ garage. They put an off-road needle and seat kit in it and double checked the floats out of the box. Should be good to go with a little tweaking on the idle and mixture screws, we'll see how she runs with it on there!

 

[okie4570]

Ended up picking up an Edelbrock AVS2 650 from a local speed shop/ garage. They put an off-road needle and seat kit in it and double checked the floats out of the box. Should be good to go with a little tweaking on the idle and mixture screws, we'll see how she runs with it on there!

Hope it works good for you. That's what I switched from to go to a qjet.

 

[SteveL]

Should do ok on the street. I tried all the recommended tweaks with the off road kit.it still didn't work worth a damn bouncing around or on angles. Worst experience was stalling out on a steep driveway exit with traffic. Had to use the starter to crank it back to flat ground so it would start. After that the 66 got a q-jet.

 

[m_m70]

My 2 cents......

I went with this - Holley 0-1848-2 - Holley 4160 (Summit)

https://www.summitracing.com/parts/hly-0-1848-2

465 CFM and didn't have to adjust much out of the box. I have two wide-ban afr gauges (one in each long tube header collector) that I tune with and only adjustments needed were at Idle which I have set at ~14 and freeway cruise ~15 with WOT ~11.5.

Just did a trip to the Sierra and from Pacifica to Auburn (mostly flat) pulled 18 mpg GPS confirmed. Now I know I'll get called out on this as BS but seriously it's what I got and a huge part of getting that 18mpg is speed. I didn't hit any traffic and kept the speed between 60 and 65. I also run a vacuum gage inside my cab and keep an eye on it. Just the resistance form 65 to 70 will drop the vacuum reading like 4 lbs and with that mpg.

Ignition is duraspark using ported vacuum....
base timing @ 15*
3000rpm's @ 35* (plugged Vacuum Advanced)
3000rpms with Vacuum Advance @ 55*

All our trucks/engines are different and this carb/ignition combo has worked best for mine.

 

[badandy73]

Reviving this thread... been running the 650 since last August, been *mostly* happy with it- seemed to take a lot of messing with the needles and springs to get it dialed in and still isn't quite right. Starts fine, idles good, runs pretty well except for right around 1200- 1500 rpm it bogs and falls on it's face. Once it works through that and gets closer to 2k it wakes up and starts pulling hard.

Most recently, took it to a reputable shop that has a lot of experience with Edelbrocks and the verdict they gave me was that the engine needs more carb. Seemed to think it's leaning out too much at that point in the powerband and starving it. They recommended going to a 750, which had me scratching my head as I questioned even putting the 650 on there in the first place thinking it'd be too much. On the carb'd version of this engine, blueprint puts a 600 holley on it and they felt the 650 would work just as well.

Only thing I keep coming back to is the accelerator pump, there's three holes to place the linkage arm into, have tried adjusting it without any noticeable improvement. The manual states the stock accelerator pump nozzle diameter for this model is .031". Are these interchangeable and would bumping up to an .035" solve my issue- anyone have experience with this, or should I be looking at something else here?