If your TB only has the one fitting, hook that one to the appropriate port on the distributor dashpot. Don't hook up the other port on the dashpot to anything. You can hook a hose to it, but run the hose to nowhere. (That's what the factory or the dealers did to stop people from complaining.) Don't just cap it, the air actually does need to go in and out there when the vacuum retard functions.
The idle bypass on the throttle body should be set to wherever it is that makes your car idle at 900 RPM.
CO spec, as I recall, was 1.5% or 2%. The only real way to set the bypass screw in the air flow meter is to use a CO meter or other good mixture meter.
Some good L-jet info can be found on
http://www.type2.com , as the later Buses used L-jet EFI.
--DD