wont start

Cylinder 1 compression is not all that low, even for a sticky valve, so I would put off looking at that. It may well just be a worn cylinder anyway, as the front cylinder in an inline tends to do that. But that is for later.

Don't use anymore starting fluid....it is very hard on the cylinder wall and rings.

Timing with 'cylinder pressure' is totally inadequate, except for a small lawn mower engine! The backfiring usually indicates either valve timing or ignition timing is off. Assume ignition for now since you have not really timed it at all.

If you have a points ignition set, then set the timing so that the point just open while rotating the distributor slowly CCW and while the . If you have an electronic ignition, then set one of the pointed star points the trigger wheel on the distributor shaft (just below the spark rotor under the cap) so that it point right at the small gap in the reluctor, again, with the timing slot on the crankshaft damper is about 5-10 degrees BTDC. This will get you close but you ARE going to need a timing light.

For points, set the points gap at .018" with the points are maximum opening. For electronic ignition, then set the trigger wheel to reluctor gap to .008" WITH A NON-MAGNETIC FEELER GAUGE. (3 thicknesses of standard copier paper is pretty close to .008".)

Then you need to figure if you are firing at #1 or #6. As said, the best way is just to pull the valve cover and see which one of those 2 has both intake and exhasut valves slightly open while the damper mark is at 0 TDC (this is called overlap). This will be easier if you rock it back and for a bit around that point. Whichever cylinder has both valves slightly open (at overlap), then you are ready to fire the other one: for example, if #1 is at overlap, then #6 shoulf be firing. With that, you can arrange the park plug wires in the right order going CW starting with the one that is firing being over the spark rotor in the distributor with the timing set as in the paragraph above.

And PLEASE do us a favor! It wastes our time to have to guess what you have as for car and year and all that. I have had to write 2 timings setups above, because that was not answered. It is not OK for anyone to ask for help and then not give important info, when asked. (We all do this for FREE.)