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Holley carb on my spread bore 440 manifold.

Iceman55

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I have a '69 GTX 440, 4 speed with 4:10 gears. Purchased a holley 700cfm dual pump and realized the manifold was a spread bore and carb is for square bore. 2 questions - is the carb a good match and is the adapter plate at $19.92 vs a new manifold going to work?
 
I have a '69 GTX 440, 4 speed with 4:10 gears. Purchased a holley 700cfm dual pump and realized the manifold was a spread bore and carb is for square bore. 2 questions - is the carb a good match and is the adapter plate at $19.92 vs a new manifold going to work?
An carb adapter will definitely be cheaper than coughing up the bucks for a new square bore manifold. You will need to verify hood clearance with the adapter. Since you didn't elaborate on the engines particulars I'll assume its a fairly stock setup, 700 cfm carb is a tad on the small side but should be okay for some spirited street driving, you'll suffer up on the big end.
I'm sure there will be some more opinions coming...
 
Just did the same to my dad's truck and used an adapter, since the intake was a split plenum I bought a 4 hole adapter vs the open style. The Eddelbrock one I used was a piece of junk, advertised as made in the USA but came in a made in China box and the quality looked the part with casting flash and porosity all through it so look before you buy. Pretty sure it would have hampered the performance had I not spent the time to fix it.
 
Put a piece of plastic wrap on your air cleaner. Put a big hunk of clay or play dough on top of the clay & put a 2nd piece of plastic wrap on top of the clay. Close the hood. Open the hood & measure how much of the clay is not smooshed. This will tell you how much air cleaner to hood clearance you have. If you have enough clearance vs. thickness of the adapter you're good to go.
 
An carb adapter will definitely be cheaper than coughing up the bucks for a new square bore manifold. You will need to verify hood clearance with the adapter. Since you didn't elaborate on the engines particulars I'll assume its a fairly stock setup, 700 cfm carb is a tad on the small side but should be okay for some spirited street driving, you'll suffer up on the big end.
I'm sure there will be some more opinions coming...
Glad to hear the carb will work ok. Assuming a 750 would have been a better choice. I came up with the 700 after plugging numbers into the holley site. Thanks for the response.
 
Put a piece of plastic wrap on your air cleaner. Put a big hunk of clay or play dough on top of the clay & put a 2nd piece of plastic wrap on top of the clay. Close the hood. Open the hood & measure how much of the clay is not smooshed. This will tell you how much air cleaner to hood clearance you have. If you have enough clearance vs. thickness of the adapter you're good to go.
Good idea. I have the air grabber set-up so I have not gotten far enough to check clearance for that.
 
Just did the same to my dad's truck and used an adapter, since the intake was a split plenum I bought a 4 hole adapter vs the open style. The Eddelbrock one I used was a piece of junk, advertised as made in the USA but came in a made in China box and the quality looked the part with casting flash and porosity all through it so look before you buy. Pretty sure it would have hampered the performance had I not spent the time to fix it.
 
I will probably go with the holley adapter since I have the carb. Hopefully a better one than you used.
 
Which spread bore manifold do you have? I'd prefer the square bore style with it's distribution characteristics for the 700 DP. If cost is the key factor, an adapter will work. Think hard about the manifold in combination with the rest of the motor.
 
Which spread bore manifold do you have? I'd prefer the square bore style with it's distribution characteristics for the 700 DP. If cost is the key factor, an adapter will work. Think hard about the manifold in combination with the rest of the motor.
 
It is a stock manifold with 4 holes in a square pattern. Budget is a factor so will probably start with the adapter and hopefully go to a matching manifold down the road.
 
I was told that the carb may not hit it's full potential with the plate adapter. True?
 
Depends on the adapter, there's test showing spacers can add performance, some adapters are not much more than just a spacer but some like the one I bought direct the flow in weird directions.

Air grabber as in it seals to the hood? That I would think would be a problem with adding any height but never had one?
 
Welcome.
One vote against using a plate adapter.
 
Apparently I didn't understand the original post saying it's a spread bore manifold. Spread bore means small primary bores & much larger secondary bores (later Mopar & many GM). I presume you mating a Holley Double Pumper to the "stock" Carter manifold carb bolt spacing. The 1/2" open adapter works, the 4 hole style probably makes a bit more HP & torque. The 700 should work very well with good tuning. Stock height air cleaner should work just fine. JMHO
 
Depends on the adapter, there's test showing spacers can add performance, some adapters are not much more than just a spacer but some like the one I bought direct the flow in weird directions.

Air grabber as in it seals to the hood? That I would think would be a problem with adding any height but never had one?
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Ok, thank for the info about your adapter. Hopefully there will be a little wiggle room with the air grabber.
 
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