500 cfm / 600 cfm
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Senior User
Joined: Apr 2004
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From: Idaho
500 cfm / 600 cfm
I spoke with a rep from JEGS about a carb for my 71 FE 360. It already has a 4bl manifold stock and I told him I wanted fuel economy over perfomance and he suggested the Edelbrock 1403 over the 1406 since i will not be pumping the hell out of the motor. He said it would probably give the performance but that the 600 would waste fuel with a stock motor. My main goal and I'm sure not the first is to try is to make it as fuel efficient as possible. But the 2bl on it right now is not enough umpfffff. Since it came with a 4bl mani then I want a 4bl carb. Is this guy correct or shall do as most others appear to have done go with the 600 cfm????????
Posting Guru
Joined: Jul 2003
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From: Colville, Washington
Well according to the carb sizing info, it looks like a 500 cfm is more than enough for your engine. That is assuming that you have no performance enhancements installed. ie. headers, cam, dual exhaust, etc.
FWIW I think you can get the same mileage out of those two carbs if they are both tuned for mileage. I ran a 650 double pumper Holley on a 352 with a mild cam, headers and a good ignition and could get 13 mpg( if I kept my foot out of it!!) The one advantage to the 600 is the ability to work with some mild engine improvements down the road if needed.
FWIW I think you can get the same mileage out of those two carbs if they are both tuned for mileage. I ran a 650 double pumper Holley on a 352 with a mild cam, headers and a good ignition and could get 13 mpg( if I kept my foot out of it!!) The one advantage to the 600 is the ability to work with some mild engine improvements down the road if needed.
Lead Driver
Joined: Apr 2001
Posts: 6,175
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From: Texas
I agree, you can probably do it with either carb.
But, if you know absolutley, the 360 will remain stock, it might be easier to tune the 500 to be the most effcient. EIther carb can be more efficient than the 2V.....once again, if you keep your foot out of the floor :-)
But, if you know absolutley, the 360 will remain stock, it might be easier to tune the 500 to be the most effcient. EIther carb can be more efficient than the 2V.....once again, if you keep your foot out of the floor :-)
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From: Idaho
So far I think everything is stock except the exhaust is dual 2 1/2" to glass pack but I want a 2 into 1 gibson with a 3" tail pipe. This should quiet it down and still run clean. I have created a fresh air intake to the stock air box. A K&N filter in the air box and I doubled up a 1/4" gasket for an 87 4bl carb from Ford that gives me a great heat barrier and a little more top end. The 2 bl has started to leak and run rough when I step on it. A cam would be a possiblity some time at rebuild but I definitely want to stay with the 360 not 390.
