Hello All. An update on my intermittent problem...

I looked at the timing this evening with a stroboscope, at idle with the distributor vacuum connected. It appears to be 0 degrees (TDC). I checked the specification value in the service CD. If I am reading this correctly, an M117, model year 1973, should have the timing set to 5 degrees after TDC. Could someone please confirm this for me?

Secondly, I noticed with the stroboscope, that it would "miss" a flash periodically. Is this normal? Is this a concern?

Thirdly (please be patient with this very basic question!), could someone tell me which cylinder is cylinder #1 on this engine? I expected that it would be the front (i.e. radiator) cylinder on the driver's side, but my distributor cap is marked in such a way that the #1 cylinder is closest to the radiator on the passenger's side. I have tried to find out by an Internet search, but can't find specific enough information - numbering seems to vary between car makes, and I can't find what I need.

May I repeat my question from the last post? If the manifold vacuum is reaching better than -18" Hg at 2000 rpm, does this mean that the seals/vacuum lines are OK? If so, what could cause the vacuum to drop down at idle?

Thanks very much for any advice you can offer,
Joe