what cfm for a 440?

[68gtx]

what cfm carbs did 68 440's come with ? looking at a new carb for my 440 basically stock with hp manifolds and a bit of a cam, total street cruiser, never gonna see the strip but may see a few stoplight to stoplight bursts lol

 

[sicksatellite]

650 is about stock i believe...i'm sure someone else will chime in with the correct oem cfm ratings

 

[68gtx]

hard to believe 650 was enough to feed a 440, i wonder if a 750 would be too much?

 

[dfarmercse]

I am using a 750 on what I think is a pretty stock engine.

Dave F

 

[WileE]

I'd recommend the Edelbrock Performer 750 electric choke carb.

 

[696pack]

hard to believe 650 was enough to feed a 440, i wonder if a 750 would be too much?

Absolutely not. One of the first things people did back in the day to their stock 440s was upgrade the carb to a 750.

 

[rp23g7]

I am using a 850 on a stock (except exahust) 440

 

[ChargerRTguy]

Mine has an Edelbrock Performer 750 and has a manual choke , but I am converting it to an electric choke.

 

[1badgtx]

I have a 800 cfm edelbrock on my GTX now...I think it,s too small...440 bored .30 over with a 509 purple shaft ,edelbrock heads with ceramic coated super comp headers...Gonna try a 850 double pumper this summer..We,ll see how it woprks out..
Petty Blue 67 GTX

 

[B5BEE]

Im running an 800 thermoquad and the car runs 12.20s in the 1/4 all day for the street you can run smaller 650/750 should be fine for your application.

 

[rumblefish360]

440's came stock with the small Carter AFB back in the day rated at a puny 600 cfm. These carbs were normal to find on the land yachts of the day since they were equiped with Hwy gears like a 2.76 ratio. These older AFB carbs had no secondary air door.

Alot depends on your gear ratio and any mods you did on the engine. As well as it's intended RPM range. What is the max it'll see? Is the engine stock? If the answer is all stock with Hwy. gears, then yes, a 600/650 cfm carb can be used without issue. If you have a higher gear ratio with or without mods on the engine and you like to get into it a bit, then a 750 will fit the bill better.

And so on and so forth.....

 

[combatsp]

You lose low end torque with a larger CFM Carb. So if you want to go bigger, make sure you have a higher stall converter, lower rear end gear ratio or weight reduction to compensate for the loss of low end torque. If you want a street cruiser and it is mostly stock, I would stay 750 or lower to maintain the low end torque and gas mileage. My father has a completely stock 440 and just upgraded from the stock carb to a 750 Edelbrock and loves it.

 

[RobLam]

I was always told 2cfm per cubic inch, I rember my freinds stock '72 roadrunner 400ci had a carter thermoquad that was 800 cfm . so thats what i have always gone by. but with todays gas prices i might go a little smaller .

 

[rumblefish360]

You lose low end torque with a larger CFM Carb. So if you want to go bigger, make sure you have a higher stall converter, lower rear end gear ratio or weight reduction to compensate for the loss of low end torque. If you want a street cruiser and it is mostly stock, I would stay 750 or lower to maintain the low end torque and gas mileage. My father has a completely stock 440 and just upgraded from the stock carb to a 750 Edelbrock and loves it.

Be aware that some of the early 440's came with 600 cfm Carter AFB's. There also secondary air doorless.

I was always told 2cfm per cubic inch, I rember my freinds stock '72 roadrunner 400ci had a carter thermoquad that was 800 cfm . so thats what i have always gone by. but with todays gas prices i might go a little smaller .

Retune the TQ. The primaries are mighty small on it.

 

[MercuryDon]

The 440 6 pack has a cfm rating of 1350 and they run pretty strong.

 

[Cranky]

Velocity is the name of the game. Small carbs give you plenty of that but run out of steam on the top end and that's why the 6 pack setup worked so well. You ran on a 2bbl carb most of the time until you stomped it and then the out board carbs came in. TQ's can do very well on a street car too. Yeah, the primaries are small but the secondaries are big....find the big TQ and learn how to tune it.