I have a 1989 F250 with a 460/5 speed and on the air filter intake box it says 10* BTDC. The haynes manual says refer to that sticker.

uh...1986 Ford F250 Tune Up Specs | eHow.com
not quite the same year though.

oh here we go:
https://www.ford-trucks.com/forums/8...ng-timing.html

There's a few articles I've found online on setting timing by ear/feel.

Did you test the ignition module or pip sensor? I changed both not too long ago. It really smoothed the idle out and got rid of a few stuttering problems I was having.

 

Solution regarding the timing. It turned out that the timing was set correct. The mechanic that check the timing assumed that the timing mark on the crank was at TDC. The mark was acutally at 10.

 

turns out that the number 3 plug wire had a hole in it near the plug. (Probably was caused when the hood cover was put back on.) It was arching at idle causing my problems. Runs smooth now.

 

Thanks for the feedback!

 

Believe it or not, they do this in California every two years as part of the state required smog check!!!!

Bob