Suggested carb size for a 426 hemi

[Meyer]

Street driven
4 speed cuda 3:55 rear gear
Close to 600 lift solid roller
10:4-1 comp
Max rpm 6200

Holley says single 670cfm is that anough?

[Oldschool]

No, not enough for that engine. What intake manifold? I would suggest something like a Holley 950 HP for that car. It will use every bit of that - and then some.

[JS29]

It has been said CID of the engine X 2=carb size. 

[Cudino]

Mopar Performance recommended 850cfm Holley Double Pumpers on their 472" and 528" crate motors, and 750cfm on their 426" crates.  Their 528" had 10.25:1 compression, dual-plane M1 intake, hydraulic lifters with .524/.543" lift.

- Wade

[RUNCHARGER]

Single plane iintake or dual plane? Stock 426 Hemis ran dual 650's and didn't bog. I think those 950's flow less than an 850. I'd be tempted to run a 1050 Dominator for a single 4 application. I have run Hemis for decades and not once did I think "dang I wish I had smaller carbs".

[Chryco Psycho]

Hemis move a lot of air , I would use a 950 CFM Proform as the smallest carb choice
1050 Dominator is an awesome carb & I woule thinking about that for sure .

[GCragtop]

950 cfm if single 4 bbl. 2x600 cfm if dual carbs.

[RUNCHARGER]

Again, what intake are you running? If it's the MP dual plane it might be best to put it up for sale before investing in a carb for it.

[Oldschool]

Again, what intake are you running? If it's the MP dual plane it might be best to put it up for sale before investing in a carb for it.

I wonder if hood clearance is an issue?

[Meyer]

The stock aluminium dualplane it came with from mopar performance... it has a 4150 street hp 850 dp on it ...

It has a issue ! when cruising its 13.7 afr when accelerating alittle hard it leans it out ,unless i floor it and it overcomes the lean spot and the sec kicks in...

The acc pump cam / nozzles has been switched back and forth but nothing is changed...

Has a 5,5 power valve in it

[Brads70]

Simple thing but is the pump arm adjusted ok? 

[Meyer]

Yes its not a off idle stumble... wich a miss adjusted pump does

[Meyer]

???

[Chryco Psycho]

So what is the intake vacuum idling , in gear if Auto , the power valve should be at least 1.5 " below that reading , What about the secondary accel pump what size pump shooter & cam . as the secondaries are quickly opened it can go lean if there is not enough pump shot , you might need a 50 cc pump / if you are near .040 shooter you might need a hollow screw , I would want a pump cam that delivers a lot of fuel fast not a long duration shot , do you have enough jet size in the rear so when the pump shot is done you still have adequate fuel through the boosters ?

[Meyer]

30cc acc pumps
31 nozzles
orange pump cams in no 2 position
9hg at idle
7 power valve
78 front jet
88 rear jets

13.1 wot afr
13.8 cruise afr