The first few months of USA R107 production were badged 350SL (I own one) but the car actually have a 4.5L M117 engine, not the 3.5L M116.

Your 380 is an M116 and would have been CIS, a 350SL would have been D-jet if its a USA M117 intake you have.

I don't fully understand what you're asking, but there are M117 350SLs because the early cars weren't badged as the convention of the time would suggest.

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