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Old 01-25-2012, 01:05 AM   #15
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Join Date: Dec 2008
Location: San Francisco, CA
Posts: 140
Re: Vacuum advance issues

Originally Posted by davepl View Post
I thought 307s were very low compression... doubt it should ping on 87 octane. You really want vacuum advance, it's not just an emissions thing. Without it you're going to have very retarted timing at idle which will heat up valves, heat up the engine, and suck for driveability. You might be able to get it to work with a lot of base timing and less mechanical advance, but then you'll be fighting part-throttle issues.
As I mentioned above, I conquered the 307 doggie-ness by using 283 power-pak heads, giving a higher 9.9:1 compression.

Yes I agree vacuum advance is valuable. This mechanic told me to just run without vacuum, and now after my research I wholeheartedly disagree with him.
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