Smog pump removal and correct size belt installation on 1993 300E2.8.

[dacia]

My air pump is dying, the second one in so many years, so I am not too keen on spending the required money to replace it especially since the odometer reads 270,000 miles. I did a search and found the thread discussing this very issue and the correct belt length, after the pump removal, suggested was 2365mm. However there is no Mercedes Benz that would require a belt with such length. Here are the multi rib belt lengths used since 1984: 1980, 2100, 2120, 2140, 2145, 2155, 2176, 2205, 2225, 2257, 2390, 2415, 2445, 2475, 2536, 2585 all in millimeters of course. So should I just go out and by the 2365 form another supplier or try the 2390 and adjust the tensoner accordingly, if it can be adjusted, to compensate for the extra length. Engine number 104.942 with the smog pump installed calls for two different lengths, either 2415 or 2475. Mine requires the shorter one 2415mm.
Any help would be appreciated.

Alex