Larry, pistons also are available in varying weight indicated by small letter stamped on the crown.... so the engine is probably both internally and externally ballanced. Adding independently ballanced flywheel just keeps the engine closer to par.

Nearby MB shop has done dozens of standard shift conversions for 300D. They tell me the most expensive part of the operation is having 300D flywheel imported from Europe.

Recently purchased a '77 280SEL stick shift Euro model.... asked about installing the turbo diesel engine... the guy told me it would be easier for him to install the standard shift in existing 300SD / 116 than it would be to convert from gasoline to diesel on account of vacuum lines and wiring harness.

__________________
'80 300SD/ w116
'79 240D 4-spd
'71 750cc Guzzi

previously owned:

'83 240D 4-spd
'77 280SEL 4-spd
'74 280/8
'72 250/8
'65 220Sb 4-spd
'63 220Sb 4-spd
'63 190c 4-spd
'61 220Sb 4-spd
'60 190b 4-spd