Squeaking out of the rear pipes - yipes!

Well timing is fine - got a new digital timing light with RPM and advance setting features ... should have gotten one long ago - took my wife to buy me one as a present.

Found that the initial timing was spot on at 10 deg adv, but the total was only 29 deg @3000. Seems the vac adv is not hooked right because hooked or blocked it makes no diff to total timing - the only way I can get 35 deg adv @3000 is to set init adv to 16 deg. It runs better now, but I can't get the idle down below 1100 rpm no matter what I do (was 800 before with init adv @10 deg).

Maybe someone who runs a street demon 625 can help me here ... the vac line is plugged to one of the bottom male fittings on the right(passenger) side of the carb - opposite side of carb from the throttle linkage. I had plumbed it that way because I did not see any other place to hook it to, but after checking vacumn there in comparison to the other fitting right next to it there is a huge diff. ...

The other fitting is giving me 15 in of vac at idle - this is where I plug my vac operated heater vent fitting (fac a/c cars has vac controls, not all manual). They work fine so this is the correct hookup.

The two fittings are identical and on the same axis (manifold vac?), but the one I have plumbed to the vac adv gives 0 in vac at idle and jumps to 15 in briefly on throttle blip, then back to zero at a steady 3000 rpm.

None of this has any affect on the chirping of out of the back tail pipes, so I will need to actually crawl around under there for a better check. But I am wondering if the noise might be detonation/preignition. Why I'd only hear this after the new exhaust though does not seem logical.

But if anyone could help out with any of this ... the vac hookup, the init adv idle speed and setting, or the chirping, I'd be obliged. Best regards,