OKay i hjvae 64 deville turbo trans. recently installed a Holley 600 cfm carb to it after the intake manifold was fixed by deleting choke tube. but because i put new heat riser on years ago and it was pricey i didnt cover the exhaust ports up to the intake. just installed new vacuum advance and ignitor 1 ignition module. But the carb and ignition seem to be okay but the fluctuating manifold vacuum ( 18 to 21 HG fluctuating) i keep getting is telling me there is a sticking valve. OR i missed something completely, if there is a valve sticking can i remedy it without pulling the heads off. there 55,000 original miles of this old girl.
p.s while i was setting the timing back to 5 degrees i couldn't get it to stay idling with car in drive vacuum advance , brake booster and modulator plugged and unhooked virtually no leaks.