71 valiant engine build, which carb to use

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Best comparison I make is telling people that I was a driver engineer for over 19 years. The fire truck I drove had a single stage 2000 GPM pump. But when I was flowing a single 1 3/4” hand line at max laminar flow, it was 200 GPM. Not the 2000 GPM it was capable of.
 
The last two posts are reasons I like the AVS2. The primary throttle bores are a little large, but I would hope the primary side would be tuned for the package to be fairly close to the expected 10-12 inch vacuum signal at idle. But bigger flow on the primary will give more power before the secondaries open when stepping into it. I would be surprised if the secondary air door would open all the way on it, either, when it is correctly adjusted to eliminate bogging.
 
forphorty said:
You should rethink your converter choice. It will be an absolute dog with that cam. You really need at minimum , 3500 stall. 4000 plus would be better.
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I hadn't considered one that high, figured that getting maybe into the 2200 rpm range would be a good choice. While the car isnt going to ever see daily driver status, it will see some summer driving, driving it to and from the dragstrip occasionally, we only live 20 minutes away. Looking at a TCI 727 transmission, as it's half the price of having one of our cores rebuilt.
 
MOPAROFFICIAL said:
Don't you understand what carburetors are rated at and the signal given by the engine you're not flowing 1200 CFM.

Go ahead and add up the six pack CFM rating carburetors and tell me how it's over a thousand CFM and all this other crap when really it's probably around 900 cfm
Pressure drop, learn'em.
Just imagine if 1200 cfm were being digested ...you're only running 13's ??
The 318 thermo... well they made many cfm rating for those and the primary is so tiny 'stronger signal=more mixing of fuel and air... that it can run that big carb, BUT it is not even opening the secondary all the way... that air door is for a reason.
You're not an idiot, but you have a sort of confident incompetence about you..
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You dream up stuff. You interpret things your own way. Quote me once where I said any engine present or past in my possession used 1200 cfm's. Waiting.....

My opinion to the OP's question was "put the 800 on and don't look back". The OP simply asked IF the 800 was too big, and I said I have 1200 on my 318 that isn't built nearly as well as his... and they work awesome! You come with a jar of horseradish with all your disclaimers... LOL.
 
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The Barracuda in my avatar has a Frank Lupo 4200 tight converter in it. Drives great. Converter tech has come so far since the old days of adapting a 8” Opel converter to your needs.
 
Penstarpurist said:
I hadn't considered one that high, figured that getting maybe into the 2200 rpm range would be a good choice. While the car isnt going to ever see daily driver status, it will see some summer driving, driving it to and from the dragstrip occasionally, we only live 20 minutes away. Looking at a TCI 727 transmission, as it's half the price of having one of our cores rebuilt.
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Just remember...a GOOD convertor will stall at livable hp stockish stalls..and only when you stomp on it will it wind up and take off at 4000 rpm. Once you get one..oh man you'll be glad you did. It will drive nice and idle tune easier.
 
That makes sense, if I'm thinking about what you're saying correctly, I can compare the performance to that like a turbo. You can drive it light to light with good manners, but mashing down and spoiling up the turbo engagement provides a better response and performance.
MOPAROFFICIAL said:
Just remember...a GOOD convertor will stall at livable hp stockish stalls..and only when you stomp on it will it wind up and take off at 4000 rpm. Once you get one..oh man you'll be glad you did. It will drive nice and idle tune easier.
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