Things to check: 1, Valve lash. I do this the old way. Turn to the BB. #1 should have both rockers loose(both valves closed)I know this is "advanced" just a bit, but both valves should be closed. There is a very good Tech Tip for this. It will let you adjust 1/2 the valves in this position. Turn to the BB again(one turn on the crankshaft) and the #6 should be loose(both valves open) The other 1/2 of the valves can be checked at this time. At this time a little valve noise would be OK.
2, Check the vacuum advance for leaking, not hard just suck on the line, slap your tongue over the tube and see if it holds. Leaks? Need a new one. Holds? Good to go. Most set ups use "ported" vacuum so no need to undo it. No vacuum at idle.
3, set the timing with a vacuum gauge, after it starts, set to max vacuum. That will be good for now.
4, Set idle speed to about 500(if you can) Turn in the idle mix screw until it stumbles(slowly) Back out about 1/2 to 3/4 turn and it should idle.
5, Get a Dwell meter and see if the dwell is about 25-30 degrees(point gap is the check here)
6, Verify the firing order(153624) it is the same for all inline 6 engines.
These should get you running and then after the "break in" you can tune it.
Opinion: Most crappy vacuum readings, are from valves set too tight. A little valve noise at initial start up won't hurt. The Dwell Angle matters, the coil needs to saturate(field must build, then collapse for a good spark). Let us know what you find.
