So if you read the other thread i bought a Quick fuel Q850 carb for $500 at our local swao meet. It was brand new in the box. What i am wondering is IF its better than what i already had, which was a 4150 series Holley. Pro Series i think they call it. 750cfm with Vacuum Seconderies.

So which one should i use?

My engine is a SBC 408, SRP Flat tops, Comp Cams 240/600 Hy Roller, Magnum Rollers, Super Victor, Brodix Track 1 Heads Mild/Performance port. MSD ect. Rear end is a 12 bolt with 373's and the tires are MT ET slicks.

What do you think?

So is the new carb a double pumper and your old one was a vac secondary?

So is the new carb a double pumper and your old one was a vac secondary?


Morning TT ,when it stops raining on a weekend take the car out to PIR and try them both ,no guessing here ,then you will know for sure,plus it will be fun testing and tuning ....if ya want PM me with your # and if I am not working will try to make it out ....Happy Motoring

You will go faster with the double pumper -- assuming of course it is tuned correctly. An 850 is not too big for a 406, I run an AED 850 setup for E85 on my 410" engine -- it has great throttle response and sixty foots real well.

OBG is right, the best way to be sure is by testing back to back, but I'm with Eric, if it's vac secondary vs DP my money is on the DP being faster, and an 850 will be fine on a 406. You have both though, give em each a try.

My 406 with the vacuum secondary was ok... went double pumper and WOW :eek: really woke it up (both were 750 Holleys). Now went with a 750 Mighty Demon.... no real testing done yet, around the block a few times, feels good, idles better, and can't wait to hit the track.

Maybe i made a mistake. The Holley is winning the poll, although the people posting comments seems to favor the Quick Fuel??

I like the look of the quick fuel so as long as its not junk i think i am gonna stick with it.

Anybody wanna buy the Holley?

Maybe i made a mistake. The Holley is winning the poll, although the people posting comments seems to favor the Quick Fuel??


If you just read the poll it looks like both carbs are double pumpers (most people assume that an HP carb is a double pumper). That is why I think you are getting so many "pro- HP 750" votes. 50-50 is about what I would expect if this poll were about a 750 DP vs. an 850 DP carb.

Good luck with whatever you decide to go with!

Quick Fuel 850. :thumbsup: