Low vacuum - should I ditch my vacuum advance distributor?

Rat Bastid

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You always use a vacuum advance until you can’t. And that largely depends on compression ratio and cam timing. Not running vacuum advance is bad policy for most anything that sees street time.

I‘ll be 12:1 on pump gas and I’m going to see if I can use vacuum advance. It will take less fuel, run cooler and make more power at cruise RPM. It’s a win-win IF I can make it happen.
 

Bewy

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The GM style HEI dist that I mentioned in post #3 comes with adjustable VA unit that starts pulling at 5-6" of vac. You should get one of these. Many big name companies make them, $$$$$, probably made in the same factory in China, same production line, different box, where they make the $80 model.
 

DemonSwede

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The GM style HEI dist that I mentioned in post #3 comes with adjustable VA unit that starts pulling at 5-6" of vac. You should get one of these. Many big name companies make them, $$$$$, probably made in the same factory in China, same production line, different box, where they make the $80 model.
Thanks for the tip, do you happen to have an example product number or link I could use?
 

Bewy

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Sorry, I do not, but Summit or Jegs should have them. Summit has the ProForm, # PRO-67040.
In the cheaper Summit range, my catalog does not show a SB Chr version, but they could have it on their website. Make sure you get a dist with adjustable vac adv. It has the hexagonal end on it.
 
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