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I have a 78 ford f250 with a 400 engine. I just rebuilt a holley model 2300 2 barrel carb to replace the stock motorcraft 2150. I got it all bolted up and realized I didn't have a spot for my vaccum advance. There's two ports on the carb but I don't know if either one are the correct one. I always thought the port was up on the metering block. I think both ports read manifold vaccum, so they won't work.
Also the jets on this carb were #68 I don't know what the correct jets are for a stock 400. The number on the carb is 4412-3
To me, (from the picture) it looks like the vacuum advance nipple on the carb was broke off and plugged - just to the left of the float window (fuel level check plug) and north of the mixture screw. Manifold vacuum is generally below the venturi while ported is above.
No where does the books show a ported vacuum nipple.
I can't find your number 4412-3 in my books - all I have is 4412, 4412-1, and 4412-2. All 500 cfm. Stock jets show a # 73 for all 3, and a power valve # 50 for all 3.
Hate to say it, but if you're familiar with using manifold vacuum to your distributor, go for it. It' take a while to correctly dial it in, but you won't be sorry. Could it be you have a screw in tube that goes to the base plate and then to the distributor is the ported vac? Check which has a female threaded dealie....could be it. I know Eddy carbs have the ported vac below, left side, and manifold vac below, right side.
The port closest to your choke should be the ported vacuum, the port under the float bowl is full manifold vacuum. (I read this on the web just now....I've never owned one of those carbs.)
If your pulling a vacuum at idle out of the ported port, make sure your idle screws are backed off enough that your throttle is completely closing (choke fast idle too).
If you have a vacuum gauge you can check yourself. I agree with everyone's comments above. Ported should have zero vacuum at idle and the other will have manifold vacuum at idle. I recommend manifold vacuum for distributor advance. Just plug it while setting initial timing. Make sure idle mixture screws are adjusted to produce max vacuum at idle while curb idle(idle rpm) is set correctly and it should idle really well.
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Could it be you have a screw in tube that goes to the base plate and then to the distributor is the ported vac? Check which has a female threaded dealie....could be it. I know Eddy carbs have the ported vac below, left side, and manifold vac below, right side.
