You may want to search on the K-1 mod which may assist your shifting woes. To my knowledge, there isn't vacuum on this tranny, but I am not sure. I am sure those that know will chime in.

another K1 thread

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04 Sprinter 140" 2500
97 F450 7.3L
97 K2500 6.5L
76 Mercedes 300d 98k original
78 300CD 133k
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