The best I can find is that the 3.5 was introduced as a 1970 model; one source says it started production in 1969, though I don't remember it being an option when my folks bought their 280SEL in September of that year. AFAIK, all the V8 coupes and convertibles did indeed have the lowered grille.

__________________
Craig Bethune

'97 SL500, 40th anniversary edition

'04 Olds Bravada (SWMBO's)
'06 Lexus ES330
'89 560SL (sold)


SL--Anything else is just a Mercedes.
(Kudos to whoever said it first)