Holley 4 barrel carburetor problem

1988 Motorhome with 1987 Ford 460ci E-350 has Holley 4 barrel list # 50174. I can not find a parts diagram showing the mixture idle screws should be two in primary if I could have a part name and arrow showing where. Then maybe I could tune this darn thing so my motorhome would run properly. The electric choke should have 12 volts when ignition is turned on and 0 when ignition is off. I am not getting 12 volts. Any help with picture diagram would help me thanks