It might have had the flapper mod done to it? http://www.rc51.org/valve.htm
The parts removed will included the vacuum tank, solenoid valve, diaphragm and hoses, and will also remove the Intake Air Duct Valve assembly.
With the flapper mod done, do you have to cap off the inlet on the throttle bodies(comes from the vacuum tank)?
Absolutely. That's where the vacuum comes from.
It's a fitting at the front throttle body.
You can plug the vacuum host at the end where it attaches to the vacuum storage tank, or plug a short piece of host and attach it to the fitting.