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650 or 800 Edelbrock AVS?

JG71B

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I have a bone stock low mile 77 400 TQ4bbl motor from a New Yorker I plan on putting in for just a cruiser. Simple Eddy intake, hedders and carb. I was looking at the Eddy AVS carbs but not sure which would be right between the 650 or the 800. Still looking up the thermoquad as of now so cfm is unknown at this point.
Thanks in advance

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Based on your description, I'd say 650 for sure. When you get up around 400 horse, I'd change my answer....
 
I don't know for sure, and 650 cfm is plenty, but I bet you've got the bigger thermoquad on that motor
 
600cfm too small for same app??
I’ve installed the 650 AVS2 on a 65 GTO with a 389 and a 69 GTO with a 400. Both run awesome. I also installed one on a 74 Cuda with a 318 and it performs great. I really can’t say enough good things about the AVS2 carbs. I’d stay with the 650.
 
650 for sure. Better throttle response for a stock 383 or low po 440.
 
They are both trouble free unless the plastic body on the thermoquad warps , the thermoquad is bigger and sounds really good when you open it up, the smaller quads were on the small blocks
 
Carburetors flow based on demand in other words no matter how large the rating you can only flow so much air because of manifold, cam, intake/exhaust size restrictions.
Problem also is that larger cfm carbs are jetted for more flow and so are usually too rich for the smaller demands.
As said before, for better throttle response, economy stay small. If it is truly a cruiser.
 
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Don't use that later lean burn thermoquad. Stick with the 650 avs.
 
Stick with Thermoquad, Just find an earlier pre lean burn one. It will outperform any Edelbrock!
 
Don't use that later lean burn thermoquad. Stick with the 650 avs.
Stick with Thermoquad, Just find an earlier pre lean burn one. It will outperform any Edelbrock!
You DEFINITELY don't want to have the TQ setup for lean burn. I didn't think of that. Maybe rejetting would resolve that?
 
Stick with Thermoquad, Just find an earlier pre lean burn one. It will outperform any Edelbrock!
That may be true, but finding a good one isn't that easy anymore. And you also need to know how to rebuild and tune one. I agree they're great, but 50 yrs old and getting scarce. There's nothing like bolting on a branb new carb for ease and consistency.
 
I vote for the 800. That TQ you're replacing flows 800 although with smaller primaries. I would also recommend a TQ, but 45 years ago as it's hard to find a good one now.
 
Over carbureting has been a bane on street driven cars for 60 years.. Too many "hot rod" magazine go fast articles then..... The correct CFM Carb will make your car run so much better than TOO big...

I am building mild 302 for a mustang project I "inherited" to make it my daily driver... As a senior in high school ( 73) I can still see and hear my instructor in Mechanics class when I drove in my A12 car after I had purchased it... I thought he was going to have a stroke looking at those three carburetors... LOL
So as a wiser and hopefully smarter guy today I did alot of research for what maximum CFM's this street driven 302 would need..... 472 CFM.....

I am going to purchase the 500 cfm 4 barrell summit carb for it... I have a feeling it is going to run well.....
 
Over carbureting has been a bane on street driven cars for 60 years.. Too many "hot rod" magazine go fast articles then..... The correct CFM Carb will make your car run so much better than TOO big...

I am building mild 302 for a mustang project I "inherited" to make it my daily driver... As a senior in high school ( 73) I can still see and hear my instructor in Mechanics class when I drove in my A12 car after I had purchased it... I thought he was going to have a stroke looking at those three carburetors... LOL
So as a wiser and hopefully smarter guy today I did alot of research for what maximum CFM's this street driven 302 would need..... 472 CFM.....

I am going to purchase the 500 cfm 4 barrell summit carb for it... I have a feeling it is going to run well.....
What do you mean? The 800 double pumper my brother bought from a guy back in the 90s worked great on the 318 it came off of! This is pure sarcasm by the way.
 
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