jmcdona

I just finished installing an Edelbrock 2711 Performer intake on my 71 Cutlass Supreme 350. When I ordered the intake I also ordered a 1405 carb. When I installed the intake I decided to put the Q-Jet on initially for testing, so that I can determine if the 2711 itself is an improvement.

Anyway, after test driving the engine runs great, - a definite performance enhancement. So my question is; - will the 1405 be a performance improvement over the Q-Jet, or will the difference be marginal? The 1405 is still in the box, so I can return it with no problem. Or, are there any other carbs (Holly of some model) that's recommended?

Any feedback would be greatly appreciated!

RetroRanger

I've run both carbs. From purely a driving standpoint, not a quantified performance standpoint, run the qjet.

My 1405 started ran idled fine it had an odd hesitation if I turned sharply left while heading downhill, but it was a perfectly fine driving car.

The qjet starts runs drives idles fine and has much crisper off idle acceleration.

AZ520

I would return the 1405 and at least get the newest design with annular boosters. 1905 avs2 is the one you want. A properly tuned Q-jet is hard to beat so you might just stick with it.

Olds64

Have you gone through the Qjet thoroughly yet? The fuel filter housing leaks and the throttle plates get worn on pretty much EVERY Qjet since they're 30+ years old now. IF you haven't done these repairs then plan to before too long.

That Edelbrock carburetor might be the way to go. It will definitely give good driveability.

jmcdona

Thanks for the feedback

I'd say my Qjet is tuned pretty well because it's very responsive - no hesitation, and i'm currently really happy with the overal performace of my 350. I was just wondering if the 1405 would be a significant enough improvement to warrant replacing the Qjet. Looks like the 1405 is going back, - I wouldn't mind recouping some of the money that I've been putting into this project anyway!

That's funny, - i just noticed the the fuel filter is leaking slightly on the line side - good call! A little yellow teflon tape should do the trick

Thanks,
John

Olds64

The only way to repair the fuel filter housing correctly is to buy a special kit with a tap and heli-coil style insert. You can have it done by some of the carburetor specialty houses seen on the internet. It isn't a cheap repair and it isn't a cheap kit.

In the past there were new fuel filter housings available with 2 gaskets. They were a Dorman part. You might be able to find one on Ebay.

The teflon tape would probably seal the leak but be carefu. You don't want to cause problems. If the teflon tape shreds it could end up clogging a jet or something.

cutlassefi

elB

I'll also add that if you've set them both up properly there will be little to no difference in fuel economy or power. The quadrajet will offer better cold weather manners and drive-ability, but a lot of people are really attracted to shiny new stuff.

And teflon tape on the threads of the inlet will not seal it properly and will make things worse. It either needs the seal replaced or the threads and sealing surfaces cleaned up.

Olds64

FWIW, sometimes folks will remove the fuel filter and use JB weld to permanently attach the fuel filter housing to the carburetor. This is sort of "hill billy," but it stops the leak. You just need to make sure you run an aftermarket fuel filter before the carburetor.