96 E 300 diesel crossover pipe fitting

[mitcheeew]

Just finfished replacing glow plugs on 96 E 300 non turbo diesel & when reassembling I noticed that the sleeve (with 2 rubber bushings) between crossover pipe connecting into EGR pipe.
Question - This sleeve appears to be a compression type & inserting it will require some persuading.One side will easily go into the EGR pipe side,while neither will easily go into the crossover pipe end. I can try some soapy water or other lub to ease getting it in, but I'd like to know if it matters which end goes where . This sounds like a question I had before my college years.Thanks