Many thanks to all who responded to my 280 questions!
I went down there over the weekend to find that the car was running better since the carb rebuild, but was still gulping fuel and running way under its potential.
Manifold vacuum was 10-12" HG, timing appeared close to the 4 deg ATDC with advance as stated on the emissions placard .
Acting on a hunch that the distributor was installed 1 tooth off (please correct me if I could be wrong)and ignoring timing marks, I advanced the timing enough to bring manifold vacuuum up to about 18", and took her for a spin- Lots more power, no overheat or pinging! I also had to back off the idle speed about 1000 rpm after advancing the timing.
Bottom line was that after all the $ spent on this car, it was running severely retarded and almost drowning in its own fuel!
the only problem now is excessive richness at part throttle during acceleration- I get a stumble and a poof of black smoke until the engine gets on the cam.
3 questions remain for discussion.
1) Since I didn't have a manual, I didn't attempt to try to reinstall the distributor. Is it possible to get these in one tooth off on the drive gear? If that's not the case, do these engines have a harmonic balancer that could slip and cause an erroeneous timing reading?
2) Intake manifold appears OK. What needs replacing is the leaky front exhaust manifold. Does this unit have a cat converter built into the manifold? Any ideas about approximate cost?
3) Not wanting to get anyone in trouble, but- would it help to remove the A.I.R. system (smog pump)and related plumbing on this engine?
thanks for your help,
'85 F-250 6.9 diesel