I have had a 143 on my 87 300DT 5-speed since I built it three years ago. I upgraded the cable and am powering an amp and two veggie oil heaters and an electric fuel pump without any trouble. I am planning to upgrade the headlights at some point too.

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1987 300D Turbo 5-speed
1991 350 SD Turbo (Frankenstein)
1957 180D (Betsy)
1976 300D (best trade ever!)
1980 IH Traveller SD33T (Resting!)
1996 F-250 Powerstroke