Is the holley version of the quadrajet any better than a normal quadrajet and are they better performers?
Thanks

 

That's a very subjective question which can only produce subjective answers.

To a person who likes and can tune Holleys but not q-jets, the answer is "yes" to both.

To a person who likes and can tune q-jets but not Holleys, the answer is "no" to both.

For whatever reason, there doesn't seem to be anybody out there who likes and can tune both Holleys and q-jets...

The double pumper version of the Holley spread bore never seemed to be able to squirt enough to prevent bog, especially if you tried one on an automatic. Other than that, they're a Holley and produce Holley-like performance when tuned properly.

------------------
82 Berlinetta, orig V-6 car, now w/86 LG4/TH700R. 2.93 limited slip. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LG4 w/LB9 block, ZZ3 cam and intake, TBD heads, Hooker headers & y-pipe, 3" Catco cat).
57 Bel Air, my 1st car. 0.030 over 396, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & Trans-Scat shift kit, 3.08 8.2" 10-bolt w/Powertrax, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.

 

the answer to both of your questions is no. holley really has no clue how to setup a quadrajet. let alone dial one in for a specific combination. i think they secretly have a wharehouse full of kids from third world countries doing assembly.

 

You're talking about the reman'd reference carb, right?
If you're good at dialing in a Q-Jet, you shouldn't have too much trouble dialing in the Holley replacement Q-Jet unless they've done a slop-job putting it together. But that's what warranties are for. (Got mine from Auto Zone, about $240) Take it back, trade it in for another. My first one was fuct, so I traded for another and it's just fine after about 1/2 hour of tuning.
However I wouldn't recommend this unit for anything other than a daily driver. I've got a double-pumper in the works for when i'm at the track.

------------------
DR Stevens
Car #1: my ride
1984 TransAm
305HO(L69) 95K & counting
750 cfm Q-Jet reman. by Holley
K&N filter
700R4/Superior shift-kit
3.42 rear/3.73 blew up!!
underdrive pulleys
Accel HEI Super-Coil
180 stat/hi flow water
pump/Jet fan switch
dual snorkel /w/ hood louver
3" exhaust of some sort
partial emissions delete
Stock-appearing radio /w/
10-disc changer
Car #2: My wife's ride
1991 Firebird/Formula
305TBI(LO3) 99K & smoking
K&N air filter
Hypertech Thermomaster Chip
more engine mods later
400W amp /w/ 12" sub

 

I have seen this carb and although it has the Holley name on it , it really is a just like any other computer controlled q-jet. I've learned how to tune holley carburators but don't know how and don't care to work on q-jets. I disconnected the computer on mine and went with another distributor and a true Holley carburator. My 383 has a holley double pumper list #6910. This carb has small primary bores(smaller than other holleys)and bigger secondaries(bigger than most). I actually use a q-jet spacer on this setup. Double pumpers are usually not adviceable for daily driving but if you tune them correctly you won't have a problem.

------------------
Big 454 72 Chevy Nova
383 86 Camaro Z28

[This message has been edited by Big454blockchevy (edited March 19, 2001).]

[This message has been edited by Big454blockchevy (edited March 19, 2001).]

 

Okay, Holley makes some carbs with small primaries and larger secondaries. This is known as a spreadbore carb. Q-Jets are spreadbores, most holley's and others are squarebores. By getting a spreadbore carb you can get a larger CFM rating carb and still have decent low RPM capabilities compared to a similary sized squarebore. The reason is that the spreadbore allows a stronger vacuum signal to the primaries at low engine speeds and the large secondaries can feed the need for speed when you want to dust off a pesky 5.0 Stang.
I like and can tune both Holleys and Q-Jets. Holleys are easier, Q-Jets are harder but can be tuned closer to perfect. If you want a carb to fit on your stock intake and want a carb that's easier to tune get a spreadbore Holley.

 

I saw in a book somewhere not too long ago that said there is an emissions legal Holley replacement for a Quadrajet. Don't recall the number (have to hunt awhile for it).

It was definetly a Holley body (not a rebuilt quadrajet) but fit perfect witht the spreadbore intake. I think it was something along the lines of a 650 or 750. I'll look into it tommorrow and get the part #.

------------------
--Steve S--
1984 Trans Am 305 LG4, 5 speed
Daily Driver, Flowmaster 80 Series
Holley 600 cfm & vacuum advance

 

I have this carb on my car an dI hate it to death!!! It is no better than stock and I could have spent the money I paid for it on a nicer carb, which I plan on doing soon.

 

Even the Holley spreadbore carbs are basically the same design as they squarebore cousins- jets, power valves, etc. Tuning them is done in much the same manner. SO.... if you think a regular Holley is better than a QJet then you will probably think their spreadbores are, too.

There are NO direct replacement for the Computer Controlled QJet, however.