I would greatly appreciate any wisdom or recommendations for the right carb for my application. The car will be limited street car:

1978 A Body: 3581 with me in it, 1/2 tank of gas
355 SBO
speed pro W31 forged flat tops
balanced
Deck Height .017 - .023
# 4 heads with 2.07/1.72 valves, bowls opened up 65cc verified
# ARH headers
# cometic .027 mls gaskets
# lunati voodoo 233/241 @.050 - .522/.539 lift LSA 110
# performer RPM intake
# compression 10.6:1
# TH350 with 2800 stall
# 3.90 locker
# most likely running Sonoco 100 available locally at the pump

I sincerely appreciate any and all help finding the best carb for this application.
Thank you.

 

Do you still have the OE Quadrajet?

 

I do. 7027157 from a 67 tornado with a 425 and also stock 78 quadrajet from the original car.

 

As much as I love Q-jets I personally think that on a modified engine they are too hard (time consuming) to properly tune for most guys. Unless you are willing to send your Q-jet off to one of the specialists who can build it to your engine specs a 750 vacuum secondary Holley would be my choice. Much easier to tune as far as changing jets, power valves etc. If you have the budget call AED and have them build one for your setup and it should be pretty close to perfect when you get it.

Just my opinion,

 

Thank you for the advice. I’m definitely buying a wideband to properly tune the car once I figure that out. I have never done it personally.

Since I don’t know which to choose are there clear advantages of vacuum, vs mechanical vs carb designs and models? There seem to be a huge array of carb choices. The motor has fairly high compression.

I don’t mind buying quality once. It would be a home run to have this little 355 run like It’s intended.

 

My thoughts are mechanical secondary carbs are better suited for all-out performance applications such as racing whereas a vacuum secondary carb is more suited to street driving.

 

Any of the Quick Fuel mech secondary 750’s should work fine.
When was the last time anybody here bought a new, quality mech secondary carb?
Most don’t know that they come with adjustable secondaries, in that you can have them open more or less aggressively.
You have enough gear, compression and converter for it. Get the wideband and tune it right, you’ll be fine.

 

Thank you guys for the recommendations. I will get the 750. I appreciate the willingness to share knowledge.

if I may can I ask which wideband those who know recommend for accuracy? Price is secondary to accuracy.

 

AEM 30-0300 is by far and away the best bang for the buck. It’s the most accurate and fastest as well.