Opinions please: Spread bore or square bore on 440?

Jakenks

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More specifically, Thermoquad or AVS clone?

I have a '78 low comp 440 in my '65 300. It currently has the spreadbore manifold with an adapter that plunks an Edelbrock AVS type carb on it. I don't like the cobbled together look of the two. My choices are fairly simple and either is easy to affect. Just looking for some opinions on the viability of either system. I've run the Edelbrocks before and they are just ok. If I go this way, I'll put a square manifold on the engine. I've never had a Thermoquad before and am wondering how folks like them. I have access to both a T Quad or a square bore manifold. Any opinions?
 
Nothing wrong with the TQ manifold.
I wouldn't call the adaptor "cobbled".
Edelbrock 600 carb. Jetted perfectly for stock manifold.
 
All good. IMO i believe the tq can be tuned for max mpg and max power. But if your just going to bolt it on and forget about it, they all have great drivability. Otherwise they would have never made it to mass production!
 
Nothing wrong with the TQ manifold.
I wouldn't call the adaptor "cobbled".
Edelbrock 600 carb. Jetted perfectly for stock manifold.
maybe cobbled is too harsh, but I don't like the look of adapters. Plus, it makes th ecarb sit up higher than I'd like.
 
Keep the AVS and go with a new intake. If your car was a 78 with lean burn etc then maybe and I say maybe the TQ. They are a traditionally lean setup carb not designed for a 65 minimal emission engine. As most here know I abhor the TQ from past experiences.
 
Keep the AVS and go with a new intake. If your car was a 78 with lean burn etc then maybe and I say maybe the TQ. They are a traditionally lean setup carb not designed for a 65 minimal emission engine. As most here know I abhor the TQ from past experiences.
No lean burn stuff on the engine and it's using a points distributor
 
No lean burn stuff on the engine and it's using a points distributor
I say go with the square bore manifold. Also get rid of the point distributor and install the factory electronic unit from 1972 to 1976. Set the engine specs to the 1976 settings and don't look back.
 
I'd put a good Thermoquad up against an Edelbrock any day! Anyone using a 600 Edelbrock on a 440 must like having 318 power or have never had a good TQ.
 
I'd put a good Thermoquad up against an Edelbrock any day! Anyone using a 600 Edelbrock on a 440 must like having 318 power or have never had a good TQ.
Let's not get carried away with your exaggeration.
 
How is the car being used? Is it something that rarely sees more than 3,000 rpm?
It is a driver car that will take occasional highway trips. Being a big *** 300 convertible with what I think is a 2.73 gear, it is definitely NOT a race car. It will see speeds of 70-80 though when on the road.
 
I rarely say this because I'm a hot rod kinda guy, but I think in your case, I would keep the AVS you have and run, if I could get my hands on one, a stock iron 4bbl manifold from a 68-69 440. They make more torque from off idle to 2800 rpm than most aftermarket aluminum intakes.

The suggestion in post #10 of the Edelbrock Performer (not the RPM) is good one and the AVS should bolt right to it. It was designed for the Thermoquad or a 4150 flanged carburetor like the AVS.
 
The suggestion in post #10 of the Edelbrock Performer (not the RPM) is good one and the AVS should bolt right to it. It was designed for the Thermoquad or a 4150 flanged carburetor like the AVS.
That's what I put on my 440, in addition to a 750 cfm Eddy carb.
 
I rarely say this because I'm a hot rod kinda guy, but I think in your case, I would keep the AVS you have and run, if I could get my hands on one, a stock iron 4bbl manifold from a 68-69 440. They make more torque from off idle to 2800 rpm than most aftermarket aluminum intakes.

The suggestion in post #10 of the Edelbrock Performer (not the RPM) is good one and the AVS should bolt right to it. It was designed for the Thermoquad or a 4150 flanged carburetor like the AVS.
I have extra stock intakes available.
 
The '68/9 is far right and the one on the far left is for '70/1. The 2 in the middle are almost worthless but I can't get myself to scrap them.
IMG_4772.JPG
 
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