If you were using one of those glass clear filters, stop. Those filters are useless. Buy a better filter. Replace it with something like this.

http://store.summitracing.com/partde...5&autoview=sku

 

check for the obvious as well:
try without aircleaner and then check when car is warm that the choke plate is fully open.
If it's half or fully closed you're limiting your airflow so that you'd get the same problem.

as well I once heard that the balancers on a classic mustang sometimes get out of whack. they move. So the ignition timing can't be set properly. supposedly they're just sitting on a rubber band. So from this try as well advancing until the engine starts knocking under high load (full throttle high hear uphill). then retard two degrees

as you said you tried 6-11 I guess you have a strobe.
so doublecheck on vaccum advance and mechanical advance. to do this:
vacuum advance:
- get rid of distributor cap. unplug the hose on carburator side. suck on the hose (either with mouth or with vacuum gauge if ya have one). the arm at vac advance should move. once you have vacuum (sucked enough), block the hose with your tounge. the arm at the advance must not move. if it does it's leaking. put the whole lot back together.
- for mechanical advance unplug the hoise going to vac advance and block the hose with a screw.
the ignition time at idle should stay constant. when you slowly start to rev up then it should start to advance. all the way up to about 30 degrees at 3500rpm (don't quote me on that, just to give you the ballpark). So latest when you are at 2000rpm the marker must have moved by a few inches, if it still is at idle ignition the mech advance is fried


kalli

 

Thanks for all the good advice, it looks like I will have a busy weekend changing out parts.

 

+1 on the glass filters, but i do use one WITH a regular filter too just as a quick way to ID potential fuel problems