I have just bought a 1970 R/T 440 six-pack Challenger. It needs a good tune-up, been sitting for awhile 1,000 miles in 10 years, but down here in Oz it’s hard to find out about the six-pack set‑ups and exactly how the system works in progression. Do you have a recommendations or references for the information I may require?
First, it needs all the usual “LOF” stuff. I’d let the engine run at fast idle with a can of sludge flush in it, for 20 mins., then drain the oil hot. Pre‑fill the new filter with oil, etc. Change trans fluid (use Type F if you can find it) + new Dacron filter, axle fluid (just suck out what you can, don’t forget a bottle of friction modifier if SG), and lube the chassis with long‑fiber sodium grease.
Also change both fuel filters and blow out the line from the pickup to the pump, then blast some strong solvent through it (lacquer thinner, etc.). Or simply replace it.
Spark plugs of course, check ignition wires (measure resistance), and inspect insulation. Replace as needed. The distributor will almost certainly need to be 100% disassembled, cleaned (remove all traces of rock‑hard grease), re‑lubed (using hi‑temp or silicone lube) and reassembled. Confirm that the mechanical advance mechanism moves smoothly and there are no leaks in the vacuum diaphragm. If it is a dual point, be sure the breaker plate ground litz wire is intact.
As far as the carbs, almost certainly the center carb will need a dunking and a kit. Because the end carb’s circuitry is simpler, you might be OK there.
The 6‑Bbl operation is pretty simple: The mechanical linkage only allows the end carbs to open (and forces them closed when you lift). The actual opening is via a vacuum signal from the center carbs to those big diaphragms.
For more info, a FSM reprint or CD is a great place to start.