My 496ho has a loud vacuum noise coming from the throttle body. It runs good, idles good. The vacuum noise just seems a little excessive compared to other 496's that I have heard. Any ideas?? The noise is not constant it will change with rpms,in gear out of gear.

Dmann:
The idle air controller for the motor is at the base of the back of the manifold and is connected to the throttle body by a rubber hose that runs up to the throttle body. I have heard some make more noise than others due mostly to throttle body to manifold alignment issues. If there is not a vacume leak and the motor idles at the correct rpm you are probably just fine. If you suspect a leak, take of the plastic engine cover and carefully spray some Berrymans carb cleaner around the throttle body base and if the engine idle speed changes you most likely have a leak.You should be able to pinpoint the leak with the Berrymans and then fix accordingly. Check all the hose clamp connections to.
Hope this helps,
Raylar

I think they all have that sucking sound, at idle mostly.
Check both ends of the rubber hose raylar was talking about. The fitting is pressed in and requires lock tight.
Both ends of mine were loose. JC

Thanks for the advise guys! I will try the carb. cleaner.