Another wild vents question

Trying to tackle fixing the wild vents on my 2001 ram 1500 4x4. I've done many things in tracking down the problems in the vacuum system and have had no such luck fixing it. Some things I have done and found

1. One bad check valve. Replaced with one from dodge, the new one doesn't seem to hold a vacuum its more of a restriction in the system in one side. The other factory check valve holds a vacuum

2. Found the vacuum line running down to the CAD was broken causing a full time vacuum leak. I plugged it at the t-fitting - going to eventually get the posi-lok kit for it.

3. Noticed the cruise control system hasn't had any problem holding the throttle on cruise, the system alone would hold a vacuum on its own.

4. I have replaced all the factory vacuum lines with new rubber vacuum lines, elbows and t-fittings except for what runs into the vacuum canister under the cowl, the cruise control line and the line that runs into the truck for the HVAC

Kind of lost as to what to check next, Kansas weather has been cold so its been hard to go out and diagnose the problem.