UPDATE: Vacuum Leak??? (all details in my thread "Thermoquad help questions.") Thought it best to start a new thread here. In my last post I was getting very low vacuum with this freshly installed 850 cfm Thermoquad 6518S I rebuilt, using a Walker kit and new pull off from Mike's. I used a Mr. Gasket adapter to my unmodified LD340 intgake. Driving with vacuum gauge inside, I was getting 5-6 in/hg with gauge T'd off the rear pull-off port. Forum member lemondana saw that my Mr. Gasket unit was for a Quadrajet and had less material at the back that can cause a vacuum leak. He was helpful and very kind in sending my a nice older solid aluminum adapter actually made for a Thermoquad. It is shaped to fit a TQ much better. I'm very glad to be using the right one, but in this case it didn't help my vacuum. I am still getting a 5-6" reading. I have listened through a small hose to all connections, and around the base of carb, etc. Sprayed carb cleaner all around to see if it affects idle. I have pinched off the vac line to my power brakes, to my PCV, to the pull-off itself, even the vac advance, everything I could find. None of these made a change. I get the same vacuum readings at any rpm. I have checked my vacuum gauge with a Mighty Vac and it is spot on. I AM supposed to be getting full vacuum at the rear port aren't I???? If so, what is going on here? My A/F readings: At idle I am adjusted to 13.5 to 14 or so. At 2000 rpm on the highway A/F is 16.5 Any part throttle acceleration goes to 17:1 This is a '73 440 carb that has the same jets and rods as were used in the '73 340's. I shouldn't be this lean. ANY IDEAS??? Edit: Also, I do have the choke flap zip tied open and the link to the secondary air valve removed. Seemed the best way to disable the choke.