yo,
As Fred mentioned, get the Calibration # and post it;
Here is one Vac Diagram;
Diagram in a 78 351M
Source: by 78brncoxlt at SuperMotors.net
A/CL: Located in the air cleaner
A/CL DV: Air Cleaner Diverter Valve
A/CL BI MET: Air Cleaner Bi-Metallic Valve
A/CL CWM: Air Cleaner Cold Weather Modulator
ACV: Air Control Valve
AIR: Thermactor, short for Thermal Reactor. CA vehicles are installed with it as standard. Air Injection Reaction is what it stands for.
AIR BPV: AIR BPV is the AIR Bypass (AIRB) Valve; also called the TAB (Thermactor Air Bypass) Valve
BV: Bowl Vent (on top of the float tanks)
CARB: Carburetor
CPRV: Canister Purge Valve
DIST: Distributor
EGR: Exhaust Gas Recirculator
EFCA: Electronic Fuel Control Assembly/ (Fuel Pressure Regulator (FPR) (not for 78)
FLTR: Filter
FPR: Fuel Pressure Regulator
IVV: Thermactor Idle Vacuum Valve
MAN VAC: Indicating Manifold vacuum-Vacuum source
MAP: Manifold Absolute Pressure
SOLV: Solenoid Valve
SV-CBV: Carburetor Fuel Bowl Solenoid Vent Valve
VAC: Vacuum
VCKV: Vacuum Check Valve
VRESER: Vacuum Reservoir Solenoid Valve
V REST on earlier years such as SEABRONC's 83 is a Vacuum Restictor/delay valve, it delays vacuum for a certain amount of time
VRV: Vacuum Regulator Valve
V CK V: Vacuum Check Valve
VRDV: Distributor ****** Delay Valve
TVS: Throttle Valve Solenoid (aka Solepot, Dashpot)
TVV: Thermostatic Vacuum Valve (aka Ported Vacuum Switches)
PURGE: Vapor Canister Purge Valve
LCV = EGR Load Control (WOT =Wide Open Throttle) Valve)
HICV = Hot Idle Control Valve
IVV = Thermactor Idle Vacuum Valve
VRDV = Vacuum Delay Valve (VDV, VRDV, DV-TW)
(VDV = Vacuum Delay Valve)
(DV-TW = Two Way Delay Valve)
HEAT VLV INT = Heat Vacuum Control Valve Intake, (next to carb)
Color Codes
Red = Main vacuum
Green = EGR function
Orange = Heat control Valve (exhaust & intake) (AKA heat riser but more complex)
Yellow = Distributor advance
White = EGR vacuum (source)
Black = Mainly used for the Evaporative emissions control
Black = Thermactor ACV or Diverter valve
Blue = Throttle Kicker control
Pink = Thermactor Air Bypass Valve (BPV