[FED 387]

timing on a engine with a chain drive will tend to retard as the engine increases in rpm and advance when the rpm decreases if you time it by reving it up its the chain stretching ever so slightly or taking up the slack that causes this movement---try timing it at a steady rpm of say 5000 rpm see what it does if its moving around or not---I'm gonna bet tht you have a bad wire somewhere either broken or bad connector maybe even a bad sparkplug try swapping out plugs one at a time see if it helps I've seen bad ones from the factory not often but it does happen---works and then kinda works depending on the load and other things---- -- maybe go so far as to take the engine back out of the car and run it on the dyno again see if the problem persists or goes away---if it persists its the engine if it goes away its some thing in the car---if its in the car then you'll hafta start looking at the entire electricla/ignition system----Comp