Put it back stock.The nylon on the gear came apart but chain did not slip.Pulled oil pan and cleaned also.The spark knock was more or less the same before and after.More consistant now and car runs good.Last tank(mpg)was 22.4 all hiway.It gets 100 miles a day put on it.I decided to check timing and its 4 degrees high.OH I did manage to get DIST.to move with PB Blaster and twisting back and forth on it by hand.The setting of timing 4 degrees back(To 0)made a BIG differance in spark knock.Its almost 100%gone.Even with ac on and lugging it.(4 speed auto and 2.89 rear gear) I'll give up a MPG or so to stop that PING which sometimes can be pretty bad.

 

I recall reading in an old GM owners manual something like "pinging is the sound of fuel economy".

 

Lite ping I could live with and yes I use to tell customers that LITE spark knock is ok.But at times before thermostat opened it wasn't lite.Bad enough to pull your foot off it and go WOW! You could watch temp gauge and right before thermostat opened it would rattle BAD.Also with in town driving it would shift to o/d and if you pushed throttle on a incline it would rattle bad like a manual trans in too high a gear before the downshift.Wife just left for her 50 mile drive to work.She'll report in a while how it did.Its really a NICE car.We added police sway bars,new paint and vinal top last year.Regular maintance and Amsoil fliuds front to rear.Bought it in 1997 with 86k on it and fading paint.Wife always gets 20plus mpg every tank winter or summer.Last two sets of Cooper tires got about 70k per set.In fact worried where we park it now.The hispanics always eyeing it and wanting to know if for sale etc.