I'm obviously late to reply and I have not done the LS swap, but still I think I might have something useful for you to think about.
My #1 biggest concern about removing a canister is that as long as the canister is present and it and it's hoses are in good shape the system is closed. Other than when pumping gas the only air going into the tanks has gone though air cleaner, and charcoal canister, anything coming out is burned off. Once the canister is gone, you may smell fumes, like on a warmer day with fuller tanks. Or when night comes and temps drop the gas contracts and in comes the cold moist air. The charcoal canister not only holds those fumes but it help to keep moisture from incoming air out of the tanks. Since most of us are still running metal tanks, this is very important.
If you have a heavy emissions year truck with a spaghetti mess of vacuum lines to the canister you could order an older simple 2 or 3 port canister that would be much easier to hook up and still protect the fuel system.
