Need help with 4 barrel upgrade

[dixyson]

I have a 258 that had the stock single barrel carb. I am replacing it with an alluminum intake and holley 390 cfm carb. On the one barrel there was a copper line running from the side of the carb to the top of the exaust manifold. What exactly is it and where on the holley would I hook it up? Any other tips or tricks to hook the new carb up would be appreciated. The single had a vacume line running from the side it to a fitting on the side of the old intake. Do I need to use this? The used alluminum intake has this fitting pluged off(located under carb).Thanks

 

[Junkpile]

RE: New Rims 15 or 16"?

Junk that exhaust manifold and get a header to go with that induction system.

Rip all of that crap out from under there and start over, using just what it needs to run.

If you have emissions testing in your area......forget it.

 

[dixyson]

'86 CJ7 Engine Wireing Diagrams

I don't have to worry about emissions testing and I do plan on getting a header when I can afford it. Right now I am just trying to get the motor running. I know I will need to run a return fuel line to my tank as the single did not have one. I will have to do this with a header also so it will not cost me any extra in the long run. I am just wondering what purpose the line to the exaust manifold is. If it is not needed can I cap it off? The single had two vacume, one fuel, and this line connected to it.