360 engine with edelbrock air gap

javcamac

New member
Hi guys.
I planing to increase my carb. What is the best cfm for a 360 engine. I have my engine with edelbrock air gap and 2bbl 500cfm.
 

The best sized carb would based on what mods your 360 has...... Aftermarket cam? Headers? Over-board (.30, .40 etc.)? Increased compression? Not really sure what an "air gapped" edelbrock is? Is it a tunnel ram? Or a carb spacer?
 
air gap is a intake manifold, thats about all i can tell you about it. What other mods are on the engine? 600cfm seems to be a good all around carb until you reach big hp.
 
Its an edelbrock 7531 and I have a Holley 500cfm with main jets size 68. Also spacer to install the holley because is a 2 bbl. Header. HEI ignition. The rest of the engine (cam, head) in stock condition.
 

Its an edelbrock 7531 and I have a Holley 500cfm with main jets size 68. Also spacer to install the holley because is a 2 bbl. Header. HEI ignition. The rest of the engine (cam, head) in stock condition.

Looked up your intake when your post mentioned a spacer , turns out your manifold is a four bbl. and that spacer must be an adapter to two bbl. . I found an on-line carb/ engine displacement / rpm calculator ( many sites for this formula ) and at 6000 rpm , the results were 531.25 cfm . Your probably on the mark with the present carburetor , if it can be rejetted as many Hollys can , it may be worth trying that which involves reading spark plugs and test drives such as 60 ft. Sprints to determine best tuning .
Tuning for performance always is trial and error , but one more factor is your trying to improve off-road performance , not quarter mile . You may be best to shop for an off-road carb that is more suited for your driving in the cfm range best determined for your engine using the formula best suited for the rpm range your engine best performs at . The manifold is said to be efficient from 1500 rpm upward to 6500 , so it seems to be well suited for the AMC 304,360 & 401 as advertised . Was trying to find an Edelbrock carb complementary for your manifold , found that trying as they were street performance . Hopefully someone can recommend a good off-road carb which is good for hill climbing and descending as float bowls suffer from fuel slosh and jets and floats cause temporary fuel starvation resulting in loss of power and possible stalls . Not good . Hope this never happens to you or anyone . Found that out years ago with a 78 jeep cherokee 2bbl. 360 myself. Fuel injection overcame that for me with my 92' XJ , but I'm sure someone in this forum could recommend a good carb for both off road and on .
Sorry I'm not much help at carb choice but I just wanted to give what I knew from my misadventures with that rig being similar to your set up now . Back then , there wasn't the choices we have now but I think that off - road problem has since been cured.
I do remember seeing carbs designed to overcome the fuel slosh problem , hope someone knows of the ideal carb for your jeep. Best of luck in your quest for performance and efficiency !
 
Its an edelbrock 7531 and I have a Holley 500cfm with main jets size 68. Also spacer to install the holley because is a 2 bbl. Header. HEI ignition. The rest of the engine (cam, head) in stock condition.

Forgot to mention , spacers / adapters do have an effect on bottom end rpm performance and idle/off-idle too. Wondering if this could be affecting performance of your jeep ?
 
It's an adapter for 2 bbl carb. For now the 500cfm run well but I want to up for the maximum performance without change camshaft or other thinks.
 

It's an adapter for 2 bbl carb. For now the 500cfm run well but I want to up for the maximum performance without change camshaft or other thinks.

Starting to lean toward a 600 cfm as that should not be over-carbed for your engine , but was wondering , do you have the engine bog issues that fuel slosh produces ? Still hoping that a forum member who has a good carb recommendation can help in your performance quest . Searching on-line has only produced sales pitches , we would be best to hear from someone's real world experience with carburetored engines for a jeep to fit your needs. Will be listening up too as this strikes a note that I consider serious having dealt with it once before and carb rebuild did not cure it for me , only slight improvement .
 
As for a offroad carb, I have personaly owned the ford motorcraft 2brl on a 304. I rolled the jeep on its side once, and the dang thing kept running until about 5 of us flipped it back over. Always seemed to run good on angles and inclines. I know their are better carbs out there for offroading such as the holley truck avenger, and I think edlebrock makes a offroad carb too. I have not tried the truck avenger or the edlebrock myself but have heard good things about them. I have a holley 650dp on my jeep now and it totaly sucks off road.
 

The quadrajet actually is a great carburetor for making power because of its big venturis (especially its secondaries ) but always wondered how it did on steep hills climbing and descending in terms of float bowl slosh. I had one on a '78 Chevy blazer 350 and was great in the woods . But never went up or down too steep of a hill since full size (stock suspension) blazers weren't too nimble . Tip easy if your not careful. Never got to find out how the quadrajet does on hills. But did just fine on minor grades .
 
I'm using the Edelbrock Performer intake and carburetor on mine with the offroad spring kit.. It works well on steep angles. I would recommend you get the needle kit as well and see which best suit your taste in performance. The only negative feedback on this carburetor would be " it sucks gas like crazy" . Running with 35X14.5 x15's gets me 8-9 mpg..
 
the edelbrock air gap has the bowl raised from the manifild to allow air to circulate under the the plenum so as to help keep the air/fuel mix cooler, I have one with a edelbrock 750 cfm on my 360, works great, main reason I went with the 750 was bought off craigslist, new for 150.00 bucks, lucky me. also picked up a supercharger scoop for 50 bucks.
 
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