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what size holly?

boneheadsGeTeX

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heres what iv got 1970 gtx 440, little off the heads, stock bore &stroke, big cam, dont have dir.#s , but can get if needed, headers, mopar wedge intake,,, im going with holley carburetor, what size do yall think I need? Dont know if it maters but have electric fuel pump
 
Would an 850 Double Pumper be too much...... ? Seems he has the support for it.
 
850 is too much based on info given. If you go to holley website there is a carb size calculator. For the street 750 is on the big end of acceptable. Depending on carb. Recommend going to the website and reading up on the different types.
 
750 Vac secondary for STREET calibration (assuming this is for a street car with a mild cam). Street Demon or similar should work well. I would not use a 750 DP for a regularly driven vehicle, but if you have a big cam (108 LSA) then you might need the DP or more of a race calibrated carb. Then that will take the streetability out of the car.
 
My QuikFuel 780 VacSec works very well for me :hello2:

We ran one of these on our "Winter Charger" and it worked flawlessly. You cannot beat the price vs. quality on this carb. Quick Fuel really hit a home run IMO.
 
agree with others, quickfuel stay under 780cfm
 
It got a 750 vac seems to be flooding out. My dad said it needs smaller cam he seems to think to much Dur. It's pulling too much gas. But now I have added the headers and intake. It's a diver, no race But that being said I want it run like a rAce car. Also Iv got to reroute gas line kinda been running thinking best rout , typ fuel rail ,? Anything y'all can say to help would be greatly appreciated
 
Throwing parts on it solves nothing. "Seems to be flooding".. what do your plugs look like ? "Big cam".. well, you should know exactly what cam is in there before doing anything else. How is the carb set ? Jets, PV, ?? What ignition, and what timing are you running ? Sounds like you're wandering around this engine, you got to get to the meat & potatoes... details & specifics.
 
Wileerobby, your right, it a 440 stock bore and stroke, msd ignition, headers , aluminum mopar wedge intake , cam is .050 240 int ./050 246 ex./110 lobe center, lift 507 int. 510 ex. Electric fuel pump,,
 
It got a 750 vac seems to be flooding out. My dad said it needs smaller cam he seems to think to much Dur. It's pulling too much gas. But now I have added the headers and intake. It's a diver, no race But that being said I want it run like a rAce car. Also Iv got to reroute gas line kinda been running thinking best rout , typ fuel rail ,? Anything y'all can say to help would be greatly appreciated

A lot of duration causes a low vaccuum situation where your carb doesnt pull as much vaccum and the fuel could be puddling in your intake.Theres a lot of tuning that can be done to holleys if you take the time to learn about them. Holley has a great tuning book. A lot of people throw a carter on because they dont want to tune. Proper jetting and airbleeds and the Holley wins hands down. If you think its flooding buy a few fresh plugs and change primary jets a couple sizes down and install a new plug. This one will be your read plug. Run it a while and pull it and read it.Each time you change use a new plug and you can see what the jet changes do. This is how to tune without an a/f ratio meter.It works. I run an 1150 dominator on the street with no problems. Good luck.
 
Holly... mistletoe and some egg nog... feeling festive ... 750 double pissah from jegs... get the mopar kit with it... you will gave to drill a hole for the linkage... and swap out the accelerator pump cams and tweak it for max performance or run it out of the box... buy a new one...
 
Is this a old 750 or new
It could be a bad float or needle and seat power valve or warped metering block
all of that is fixable but you need to identify what is causing it
 
The one that was on the car, was one that I dad had laying around , he spaid it was a 750 vacuum, it looks like crap , iv put new headers intake ,on so now time for carb, just havent mad up my mind witch on ,,, Sleeper I like the sound of a 750 with mopar kit,, what the kit for? Jets?
 
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