Gentlemen,
I have in front of me an Operating Information Memo issued by Lockheed in May 20th 1980 called "Wing Engine Pod Motion" and a Notice To Operators issued by Rolls Royce on the 22nd of May 1981 called "Engine Thrust Oscillations". Looks to me like it will answer your questions.
A fairly long one to type, unfortunately no time doing it today, but I could have it posted in next couple of days. Interested or not???. .Cheers!!!