Hello,

Upon searching mbpartsworld it is showing 0028355201 as the part number to replace the heater core in 1978-1985 300SD among other models.

Is this accurate? To my understanding the 1978-1980 300SD had copper heater cores . I know that the radiators are copper (only made for the 79-80 300SD). Can a copper radiator and Aluminum heater core be mixed like that? Or does it have to be copper radiator and copper heater core?

I appreciate the help that has been given on this forum!

__________________
Nosce Te Ipsum "Know thyself"

I'd recommend you get access to the online EPC, free here for U.S. residents. You can plug in your VIN, and get exactly the part number for YOUR car:

EPC-net Online

I don't think the cooling system cares about the metal in the radiator, block/head, and heater core, as long as you use the proper MB-spec coolant and change it on schedule.

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Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC