On W124, which blower motor to get seems to depend on whether or not one has a pollen filter. Am I correct that, in both cases, the motor itself is exactly the same and that the difference somehow has to do with the squirrel cage assembly? If so, what is that difference?

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 154k miles
06 E320 CDI "Rutherford", Black on Tan, 172k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver, 142k mi, wastegate conversion

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife