Just make the thing scream. Yes, the M103 is pretty weak below about 3.5K rpms. Keep the revs up and it's fine. It almost has as much hp as the contemporary 420, and it weighs a bit less. Making overall acceleration theoretically par for par.

I had no problem with the SE when I had it. And I was perfectly comfortable with the power. You just have to keep in mind, at what point in the power band you get the most shove. An engine like this would've been perfect with a manual transmission. And the revs never bothered me...The engine was designed to be a screamer in the first place. You're not gonna hurt it.

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1987 300SDL (324000)

1986 Porsche 951 (944 Turbo) (166000)

1978 Porsche 924 (99000)

1996 Nissan Pathfinder R50 (201000)