Agree with Haasman 100%.
The head in my car was done years ago, compression due to shaving at around 200 psi on all cylinders. Bad idea to use 87 octane at that compression. Can probably run Diesel
Do a compression test, and take it from there.

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1999 Porsche 996 Carrera Convertible
1994 420E - SOLD
1986 300E - SOLD, what a car
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