I just picked up my vortec heads from the machine shop and the engine builder I talked to said I could make about 40 hp more with a quick fuel carb than the quadrajet. He also said the quickfuel 650 would be about $350 new where as the rebuilt quad would be $220. He's reputable in the area so I trust his experience. I already have a performer Intake for the spreadbore though I could return it and get an rpm performer for a squarebore. I've got no experience with carbs fwiw. Would the hp difference be that significant? Any input would be greatly appreciated.

 

to me the easiest one to learn and tune is the holley type, there are tons of books, and info online etc. lets put it this way i have a quad sitting on the shelf and 750 holley dp on my car. and i could have someone who used to work at rochester help me tune it.

 

i like mechanical secondary, mechanical choke because its easy to figure out in the pit if its working. if you are going to be making 350-400hp i would recommend a 750.

http://www.summitracing.com/parts/hly-0-4779c/overview/

 

The only way to know this is tune each carb to the engine then test on a dyno, 40 more hp from just a carb swap IF the Q-jet is tuned correctly is hard to swallow.

I haven't a clue why people think the Q-jet is so hard to work on or tune, there's many books and how-to's out there, all one has to do is read and learn.

I've been tuning/run'n Q-jets for over 30 years and IMO their the best bang for the buck......

 

were this a swap from the non-vortec perfromer to the non-vortec rpm along with the carb swap, I could see some noticeable gains. i suspect the difference between the vortec performer and rpm is not quite as great though, based on the taller intake runner for the vortecs. i hope to one day see some actual comparison numbers, but oh well.

if you do go mech carb bear in mind that you will also need to replace your disturber for a mech/vac advance one. converter lockup will also need to be accommodated some other way. the ecm and all of its associated wiring can then be removed. something of a crossroads here with the intake choice.

 

also, they do make carb adapters if needed.
http://www.summitracing.com/parts/edl-2696/overview/

 

I am going mechanical and already have the non ccc dizzy. And I've heard nothing bad bad about the adapters.

 

You will be lucky to see 1-2 HP difference between the two carbs if both are even close to being dialed in well. The Q-Jet is at a minimum a 750 cfm carb and many are 795 cfm and a few 830 cfm as well.

I find the Q-Jet easier to work on than the Holley.

 

Thanks for all the input. I'm just gonna keep my manifold and get the rebuilt quad as planned.

 

You won't be disappointed. Once I learned how to tune a QJ, it was actually pretty easy. Performance wise, I've been pretty pleased.

 

yup