Beats me. If I had to guess, I would say 1975-76.

I do know that my '73 280C had the old style and my 1978 280SE had the new. The EPC shows breakpoints for cams and cam boxes for injected and carb'ed engines. For example, for the 110.985, it's #16848.

There is a special kit to block the oil passages of the bottom of the cam box if you need to put a new-style cam in an older box.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe