The early CF6's were probably too long (although I don't fully understand that...), but about 1983 some L-1011 operators were shall we say fed up with the maintenance cost of the RB211.
Delta and All Nippon had large TriStar fleets and had bought early 767's with CF6-80A's, which were a foot shorter than earlier CF6's due to new combustor design.
So these two carriers were very interested in retrofitting the 1011 with CF6-80A's - but they couldn't achieve a critical mass to convince TWA or others to join them.
