Altitude and timing

[jhersey29]

I spoke with a mechanic today and he's the first one to recommend a timing change. The timing is set at 5 degrees BTC. He recommended adding 3 degrees for altitude and setting the base timing at 8 degrees BTC. Can anyone confirm? I've read some auto forums and people are saying 1 degree extra per 1000 feet on the base timing can help solve some altitude issues.
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