Holley 3310 750cfm

[dodj]

Ive had this carb for a long time. But I don't think I've gone through one trouble free cruising season. today as I was on what is probably the last cruise of the year, I had backfiring on deceleration.
When I parked at home, I found there was gas seeping from the rear float bowl. Air bleeds were wet. Gas pooled on the intake. I had checked float levels 4 weeks before.
Are all holleys this problematic? I think I'll go proform or??? next year.

[Chryco Psycho]

the Holley design can be problematic , the cars sit too much in Canada the gaskets dry out , powervalve diaphragms harden etc , gasket tech has improved , the fuel is much worse with all the alcohol in it . Just installing a new kit with all new gaskets & parts like needle & seats & powervalves will help for a year or 2
. Many switch to Carter / Eddy design as at least the fuel cannot leak out but the tunability is far worse .
Proform / QFT is the best I have found , Proform is slightly cheaper & they are both great for tunability .
 the ultimate is multiport EFI of course .

[dodj]

the ultimate is multiport EFI of course .

Well I agree with that but it's a little pricey for me at the moment. With a 440, 4 sp, 3.55 gearing, what cfm would you recommend 950? 850?

[Chryco Psycho]

850 cfm assuming you are redlined around 6000
 the 3310 is one of the oldest designs of Holley carb dating back to the 60s , they are decent or they would not still make them but you can definatly improve

[cudabob496]

I'd go mechanical secondaries

[brads70]

This is what I have. Best carb I've owned so far! 
http://www.quickfueltechnology.com/carburetors-q-series/q-series-carburetor-850cfm-drag-an.html

[dodj]

I'd go mechanical secondaries

How come? I thought, when properly set up, vac sec was better. From Brads post, he agrees with you.
School me.

(By the way, not a cheap carb Brad  )

[Chryco Psycho]

I have always preferred mechanical secondaries as well , you may or may not be able to floor the throttle from idle but punch it wide open at 2000 rpm & it will hit a lot harder than waiting for the vacuum to open the secondaries

[cudabob496]

How come? I thought, when properly set up, vac sec was better. From Brads post, he agrees with you.
School me.

(By the way, not a cheap carb Brad  )

secondaries are discussed here:

http://www.hotrod.com/pitstop/1306_vacuum_or_mechanical_secondary_carburetor/viewall.html

http://holley.com/TechService/FAQ.asp

[Super Blue 72]

secondaries are discussed here:

http://www.hotrod.com/pitstop/1306_vacuum_or_mechanical_secondary_carburetor/viewall.html

http://holley.com/TechService/FAQ.asp

Nice links, cudabob! 

[mopar jack]

I've used the same 3310 holley on my 440 for 16 years and it would leak at the bowl gaskets on a yearly basis. However over time I have upgraded gaskets and at the start of spring I check the bowl screws for tightness and no issues.


Jack

[HP_Cuda]

Vac secondaries are great if you don't like dumping a boatload of fuel all the time.

 

[brads70]

.

(By the way, not a cheap carb Brad  )

True , but if you want to "play" then ya gotta pay? I have a 3310 here all rebuilt and ready to go. I ran it for years on my 383 Chevy. Worked OK....

[HP_Cuda]

Hey Brad

I remember you had a jetting problem with that carb, did you go up or down in jets?

B

[brads70]

Hey Brad

I remember you had a jetting problem with that carb, did you go up or down in jets?

B

Down in the front but up in the rears, had a heck of a time with squirters though. Used a really big on in the back to get rid of the bog. Finished with tuning the pump cams... still not perfect but much better. Every engine/location will be different though.