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1970 Calif tank => venting options

JS23U

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I own a 70 Challenger R/T 440 with ECS aka California emissions. It got its fuel tank replaced some 35 years ago with a 49 State item, the venting was accomplished by drilling a small hole into the ECS gas cap. The 4 fuel tank vents were disconnected as the tank didn't have the four vent nipples anymore. The vapor line going to the engine bay (inner passenger fender) was cut off somewhere at the front frame rail. So the car was run like a 49 State car, which all worked fine.
Years ago I bought a new fuel tank and finally installed it, this time the correct California tank with the 4 vent nipples on the passenger side. I would like to reconnect the vapor cannister in the trunk. But the vent line to the engine breather is not completely there, as written above. Will the system work with just the 4 hoses reconnected to the canister as long as I continue using my drilled fuel cap? Or should I invest in the vapor line to the inner passenger fender and connect it to the breather? I already have the 3-nipple breather, currently with the two small connections blocked. Carb is aftermarket QFT without a venting connection. On the breather just the big connection to the air cleaner is used.
I assume the carb doesn't play any role. So I can leave that third nipple on the breather blocked, right?

The car is a driver, has headers, QFT carb, single plane intake and so on. Also, the vapor separator currently is not installed, if that matters. I run an aftermarket fuel filter.
What are my options?
1) block the 4 vent nipples on the tank and keep everything as before
2) connect the 4 hoses between tank and separator, block the fifth line coming out of the fuel separator tube, use the drilled fuel cap. Will that work?
3) buy a vapor line and connect it to the breather, buy a non-vented fuel cap. This would be like stock ECS except for carb venting

I'd prefer 2) if it would work.

Are my thoughts correct and would all those options work? Any other options?

Thanks.

Cleaner Air System.jpg
 

smm91761

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Just had this issue last night, filled the tank and it was pissing out of the PVR cap…. Going back to the shop this week…. 🙄
 

Steve340

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I think it is a bit of work for sure but go back to the stock system.
I does work well.
 

ScottG

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Options 1 and 2 are really the same in terms of the tank. Hooking up the 4 lines to the ECS tube in the trunk and then blocking the line to the engine compartment effectively seals that volume, just the same as capping the 4 tubes at the tank. In either option 1 or 2, you still need to run a vented gas cap to keep from pulling a vacuum on the gas tank (or pressurizing it with heat).
 

JS23U

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Thanks for your replies. I think I will go with #2 for now. I still can upgrade to #3 later on.
 

cuda joe

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for #3 the vent line probably still there from the back up to under the cowl that is where there is a small rubber hose connecting to a steel line that goes up to the inner fender then a rubber hose to the 3 nipple not much to do to get it working again .then a non vented gas cap and no more gas sloshing out the drilled gas cap
 
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