I hope someone can give me some info on carbs. I am building a 77cj7 and want to convert to 4v. I have already changed intake. I am just wondering what would be a good carb for this. Probably a 600 cfm. I have the stock 4v intake from a amc 360 i would like to know makes and model #s if anyone has those. Also in the market to buy. Any help will be appreciated thanks
304 4v
- Thread starter CAPTDONFD
- Start date
SteelHeadz
Super Moderator
I installed the Edelbrock performer intake and the Edelbrock performer 4 barrel on mine. I've been thinking of changing the intake to the Airgap but that's low on my priority. I dont know if the Edelbrock will just bolt up to the AMC intake. It's worth every penny..
dave123
New member
I would suggest that you go with the smallest 4 barrel that will fit. The 304 is not a high RPM motor and does not require a lot of carb. There are charts that you can find on line that can tell you the correct CFM. Here is an example.
http://www.4secondsflat.com/Carb_CFM_Calculator.html
Your volumetric efficiency is probably less than 80, and your maximum safe RPM on a stock 304 is around 4200 RPM. You will see that almost everyone gets a carb. way too big.
Is your manifold a spread bore? (Primary holes in front smaller than secondaries in back).
If so, get a carb to match. I would go with vacuum secondaries, and I would look for an off road carb like this:
http://www.holley.com/types/Truck%20Avenger%20-%20Aluminum.asp
This carb will handle steep grades without flooding better than a regular carb.
I have had 3 CJ’s with 304's. One with a holly 600, one with a holly 500 (2bbl), and one with the factory mc2100. The one with the mc2100 ran the best.
Just my .02 cents worth.
Remember that info on the net is worth just what you pay for it, but I hope this helps some.
http://www.4secondsflat.com/Carb_CFM_Calculator.html
Your volumetric efficiency is probably less than 80, and your maximum safe RPM on a stock 304 is around 4200 RPM. You will see that almost everyone gets a carb. way too big.
Is your manifold a spread bore? (Primary holes in front smaller than secondaries in back).
If so, get a carb to match. I would go with vacuum secondaries, and I would look for an off road carb like this:
http://www.holley.com/types/Truck%20Avenger%20-%20Aluminum.asp
This carb will handle steep grades without flooding better than a regular carb.
I have had 3 CJ’s with 304's. One with a holly 600, one with a holly 500 (2bbl), and one with the factory mc2100. The one with the mc2100 ran the best.
Just my .02 cents worth.
Remember that info on the net is worth just what you pay for it, but I hope this helps some.
If I recall correct the stock intake requires a Carter Thermoquad carburetor (AKA biggest piece of &*#$) carburetor ever made, even worse than a Quadrajunk. My recommendation to you would be to use an aftermarker squarebore carburetor and go with a 470 CFM Holley Truck avenger.
Turbogus
Active member
When I purchased my ole '78 it came equipped with Edelbrock carb and intake. Despite needle and seat changes it wouldn't run full song. Also noticed the mixture screws wouldn't fully lean out (to the point of zero fuel). Ultimately a carb fire and subsequent fire extinguisher residue made for a sticky mess.
Luckily, I had purchased back from a friend an actual Carter AFB~Black Stallion
(powder coated) from my old Chevy 350. He could never get it to run on his 327, so when I bought it back, I simply lean out the needle/seat and put the next step up (stiffer) springs into it and whiz~bang! Been running well ever since. Not to rank on Edelbrock for the expansive help they gave me in removing a pipe plug from this manifold, but I'm dubious about their AFB clones.
Luckily, I had purchased back from a friend an actual Carter AFB~Black Stallion
(powder coated) from my old Chevy 350. He could never get it to run on his 327, so when I bought it back, I simply lean out the needle/seat and put the next step up (stiffer) springs into it and whiz~bang! Been running well ever since. Not to rank on Edelbrock for the expansive help they gave me in removing a pipe plug from this manifold, but I'm dubious about their AFB clones.
