When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Looking to replace my cast iron intake and installing aluminum on my 1969 350/350 coupe, running big block hood so I have more clearance, was going to stick with the Quadrajet carb. any recommendations? My engine is stock bored 30 over with 11:1 compression.
Thanks
You will be limited to "Spread-bore" design if you keep the Quad.
Because of your newfound hood clearance, the Eddy Air Gap is hands-down the best on the market. But again, it's a "square-bore".
A nice Holley sitting on top of an Eddy is like icing on the cake. S-w-e-e-t-.
Last edited by HeadsU.P.; Dec 20, 2022 at 07:04 PM.
any that use the original divorce style choke? I think the LT1 manifold does but takes a Holley.
If I do go with a Holley what is Recommended for the 350hp? like a 650 or larger?
Last edited by 67tripower; Dec 21, 2022 at 12:21 AM.
Reason: added line
Agree with others. Air Gap and Holly (or Eddy) carb, but even with BB hood (non-L88), it will be a tight fit. You may have to play with drop air cleaner housings to lower the carb height to compensate for the added height of the Air Gap.
But the Air Gap just looks mean and is all kinds of awesome.
Last edited by Corvette-ZL1; Dec 21, 2022 at 11:09 AM.
I would stay away from a drop air cleaner base as they take h.p. AWAY.
I don't think that's true if you stay with a 3" air filter. Plus, nobody uses a drop base for aesthetics. They do it out of necessity to address any hood clearance issues. Depending on the setup, you simply may not have a choice if you want to go with any performance intake with higher than stock profile, and the BB hood (non-l88) doesn't give a whole lot of extra clearance over the stock small block hood.
Maybe an inch, as the rise really happens toward the front of the (BB) hood - well past the carb area... I have both to compare side by side, and there ain't much of a rise where you need it.
The LT1 had a hi-rise intake, which necessitated the use of the BB hood in the first place. Easy enough to measure when the OP installs the set up that he wants and gently closes the hood - Some Playdough and a tape measure or ruler should fit the bill.
Last edited by Corvette-ZL1; Dec 21, 2022 at 12:23 PM.
This is a picture of the air gap on my big block with a Quick Fuel 850 cfm dp sitting on top.
Notice there is no choke and manual secondaries on this model.
I will also be adding a 1” spacer between the intake and the carb to help with any heat issues.
The last two pictures give you an idea of the height of the Air Gap intake.
Last edited by OldCarBum; Dec 21, 2022 at 12:43 PM.
As ddawson said Edelbrock 2101 , also comes in polished version 21011. This is a Spreadbore intake. If you have a good quadrajet I would keep it. There is no aftermarket Edelbrock or Holley carb that will come close to running proper AFR like the Quadrajet . You will be buying a gas guzzling carb with little to no increase in performance. Even with extensive work these carbs only come close.
You can always run an adapter plate to make a GM Quadrajet or a Holley 4165 fit on the Air Gap or any other square bore intake. That's what I did with mine.
Believe it or not, my 383 stroker loves the Holley 650 that's been my carb for ten years. I've tried 750's and it was too much for it, even jetting it down. For 350 horse, IMHO, a 650 will work fine. You have to find a carb that the engine is happy with. My '74 with a 3:50 rear end, runs 13.6's at the drag strip. It pulls hard all the way to 6K RPM. Regarding the choke, I have the Quadrajet style Holley 4165 Mechanical Double Pumper and it's never had a choke at all (choke delete). Instant start and except for when the weather is really cold, idles immediately at 500 RPM. A well tuned engine, shouldn't need a choke to start right up. In the Winter, I do have to feather the pedal for a bit until it warms up and then it's fine.
Edelbrock 7104 RPM Q-Jet. Not an airgap but works great. You won't miss the 5-10 hp from an airgap on the street. Used to run this with a Moroso Aircleaner (about 1" drop) and 3" filter under a '75 hood. Same height as a BB hood.
Believe it or not, my 383 stroker loves the Holley 650 that's been my carb for ten years. I've tried 750's and it was too much for it, even jetting it down. For 350 horse, IMHO, a 650 will work fine. You have to find a carb that the engine is happy with. My '74 with a 3:50 rear end, runs 13.6's at the drag strip. It pulls hard all the way to 6K RPM. Regarding the choke, I have the Quadrajet style Holley 4165 Mechanical Double Pumper and it's never had a choke at all (choke delete). Instant start and except for when the weather is really cold, idles immediately at 500 RPM. A well tuned engine, shouldn't need a choke to start right up. In the Winter, I do have to feather the pedal for a bit until it warms up and then it's fine.
Really? (not trying to be argumentative - just surprised and generally curious) My brand new dressed Blueprint Engines 396 SBC stroker I recently bought came with a 850 Holley, which is what they recommend if you just buy the long block from them. I bought the dressed motor, and that's the set up that BPE had on it when it was dynoed.
Not sure what you are putting out at the crank, but my motor was dynoed at 500+ HP and well over 500 ft lbs of torque, so 650 would be too light for that application. 650CFM is a bit light for a 383 stroker, unless it's a really mild build that doesn't have a terribly high rpm capability (say 5200-5500 RPM max). 750 CFM seems to be the magic number for ~400HP sbc strokers.
Last edited by Corvette-ZL1; Dec 21, 2022 at 02:04 PM.
True, I have a mild cam set up with the 3:50 rear end and more set up for torque on the bottom end, with a Howard's Cam at 5.25 lift. Making about 415 HP, but as stated, the motor is 'happy' with the carb that's on it.
As ddawson said Edelbrock 2101 , also comes in polished version 21011. This is a Spreadbore intake. If you have a good quadrajet I would keep it. There is no aftermarket Edelbrock or Holley carb that will come close to running proper AFR like the Quadrajet . You will be buying a gas guzzling carb with little to no increase in performance. Even with extensive work these carbs only come close.
You better watch a few episodes of Engine Masters dyno pulls. You don't see Brule' slapping a Quadra on those high horse engines.
And if you are concerned about gas mileage, don't own a Vette.
You better watch a few episodes of Engine Masters dyno pulls. You don't see Brule' slapping a Quadra on those high horse engines.
And if you are concerned about gas mileage, don't own a Vette.
A quadrajet shines at an RPM the dyno can't even measure. So it's not ideal for power making youtube dyno tests.
intake recomendation
