Hi All,I have a 64.5 mustang 260 stock distributor,car seems to ping alot going uphill .Checked timing with gun ,checked dwell with meter set at 27 degrees reved motor to appro. 2000 dwell went to 17 degrees .I think up to 3 degrees is OK but not 10.Is the cam warn out if so can I replace it.Any help would be appreciated.Thanks Roland.

 

Don't take this wrong.
You're worried about the cam when this is the 3rd millenia and you are still checking dwell?
Go electronic, then worry about the cam.

 

It may be that the spring is worn. Are these old points. I understand wantiing to keep things origonal but, I think you should update to a pertronix unit. You will be much happier.

 

god, i feel really naive, but what the hell is dwell?

 

I will go out and pick up a pertronix unit and see how that works,will get back to you all and let you know how it worked Thanks for the help Roland.

 

LOL dont feel bad the name is a lil confusing its not your car thinking on something.
Its the point gap. In the old days we had dwell meters you could hook up and set the gap while the engine was running thru the lil door on the dist cap.
I think its been at least 10 years since my dwell meter was used.

 

When the dwell changes like that it is usually a worn bushing on the dist shaft. Pull the cap and try moving the shaft back and forth. If it changes the point gap it's bad.