My 340 getting 6 mpg

I'm pretty sure that when I was there working on the car I dropped the butterflies and only raise them a little each one so that they're probably in the idle circuit just fine. The car was a mystery carb used he bought it already had like 65 in the primaries we didn't even get into the secondaries to find out if it had a second power valve for instance, or what the Jets even were on the secondary. It was just a tune to get th3 cam broke in and a decent idle for the test drive part. It's still fresh.

The thing may have a secondary power valve and now is sitting at 67 primary and 65 secondary with who knows what power valve in the secondary but we don't know cuz we haven't gone into it yet. I gave instructions on what to start doing and he wants a second opinion is why this thread was started. Keep in mind none of the instruction has even been done yet though/yet.
All good.
I'll be driving up to do it myself and nip this in the bud.