Adding Evaporative Controls to 273 2B

Thank you for the comments.
I do not think there are leaks, but the spill to the bores is possible. I get what I think is good mileage, about 19 MPG with about 60% stop and go, and 40% Interstate at 70 MPH. I also run the A/C 50% or more of the time. I do not have vapor lock or starting problem when warm, it starts instantly. I do have to crank it a few seconds to get fuel after a couple days parked. Part of my problem is the gas was old at the start of driving season and the smell was terrible. It has improved some since then.

I had an Omni with a carb that had a similar return filter. Does it have a small orifice in the filter for the return path? Since I will extend the existing tank vent, I might be able to use it. The canister is above the vent, and tank, so if I do Y below the canister, it might work. edit: It wont work, now I understand the need for third line.

Other than running the vent line and the mount for the canister the hook-up is fairly simple. I have the Holley 2280 rebuilt. I think it will bolt on with minor adjustment of kick-down and choke linkages. The Omni used a thermal vacuum valve to inhibit purge when cold. I will try without first, if there is a problem I will add something similar, with a solenoid valve.