If I were you, I would find some 617's from pre '81 cars. No EGR, otherwise identical, and the trannys do not have the vacuum modulator to deal with. I wish I had a couple weeks off; I would give you a hand with the project….

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1983 Mercedes 300SD
1987 Mercedes 300SDL
2001 VW Passat 2.8 AWD
2007 OM642 Jeep WK 4x4