Hot Rods 780 Holley double pumper or 800 Quadrajet?

I live in an area where the population is served by three auto parts stores. Not one of them carries carbs or parts in stock. It all has to be ordered in. For the last two years, I have been ordering all my stuff on the internet.
Bob

 

I could swear that I read somewhere that the Qjets were designed with the smaller primaries to help fudge the MPG ratings as per government standards in the late sixties going into the seventies. That they estimated MPG by keeping their foot out of it and listed the car as "x" mpg but we all know that when you mash the pedal to the floor, that number went away real quick.

 

1ton,
I can't remember the flow rate of the Qjet primaries, but I am no lightfoot, and I don't find that I lose any performance with the QJet. The problem is, that there is the eye candy look to the Holleys.
After running them all these years, I know enough about Holleys to know that the moment that the mileage starts to suffer, and all other parts of the carb functioning normally, it is probably the power valve requiring replacement.
Because it has been awhile, I can't remember exactly what vacuum I ordered for the last power valve, but I think I changed from a 6 or 6.5, to a 5, which noticeably improved the mileage for driving in a mountainous envioronment. You can also adjust the springs for the secondaries of the Holley, so they can open either more quickly (at a higher vacuum), or later (larger throttle setting and lower vacuum). This can significantly improve performance or mileage.
For street use, I prefer the Holley with the vacuum secondaries to my double pumper with manual secondaries. The double pumper is a performer, but it is a gas hog.
It takes a lot of experimentation to get both economy and performance, and I have stopped worrying about it.
My tip for the best functioning carb, is to buy one of the excellent tuning books for the carb you are running, and take the time to learn how complex a carb really is. Don't let some back yard "expert" screw with it. A lot of people bad mouth a particular brand, because either they, or one of their friends has screwed it up, and they are not willing to admit it.
In the end, it is all magic. (magic being defined as knowledge and careful modifications).
Bob

 

Yes.....

 

Not likely, no one gave a crap about mileage until 1974, and the Qjet was designed in the early-mid 60s. Mileage standards happened long after the carb was designed.

 

Yep, I remember being in Laredo in 1972, with gas at 23 cents per gallon. When the OPEC embargo happened in October, I remember line ups for blocks at every service station. It was a big change, and things haven't been the same since.
Bob

 

I vote Q-jet

 

Another vote for Q-jet. It's the best street carb ever made. Easily tuneable for economy and performance. Nothing ugly about them, beauty is in how it functions. Q-JET.

 

Google the name “Lars Grimsrud” he is a very respected Q-jet expert. He will rebuild your carb, test it and send it back to you for a very fair price.
https://en.m.wikipedia.org/wiki/Lars_Grimsrud
I can get his contact info if you’re interested and can’t find it yourself

 

I also vote for the unloved Quadrajet. One of the most advanced carbs ever produced. I love them. You have to be smarter to work on a Qjet than Holley, but the effort is worth it. The triple booster venturi is a very neat, advanced feature. And the sound one makes when you put your foot in it is really cool.


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I can't remember what they were on but I seen a tunnel ram on something on the net with 2 QJ carbs on it, I'd never seen that before.

 

Would a Edelbrock 1413 Performer 4 Barrel Carburetor, 800 CFM
Be a good alternative?

 

BaWaaaaaaaa! Had a friend with stock '69 Olds 98 except for a flipped air cleaner lid, leaving an inch gap. He would punch that thing and laugh the entire time the secondaries were open, which was a long time in that barge. Just loved it. RIP Doug.