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Discussion Starter · #1 ·
Does enyone know what the vacuume should be on a 454 at 800 rpm
and also at 2000 rpm. all stock equipment. with new diff springs for total advance
Gage on manifold.

This is a car that has had the manifold off and cleaned up
and the carb was rebuilt by lars a very good job. dizzy rebuilt by big 2bird also a very good job. Ran very fine for about 400 miles then started (at idle) changing rpm and timing. The bolts were re torqued and thay needed it... car runs better with the vac to the diff disconnected.

Diff disconnected
800 rpm bounces + or - 50 rpm
vac is 17-18
timming is 26 +or-

2000 rpm vac is 20
timming is 37
??????
did I blow a intake gasket?
 

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Discussion Starter · #3 ·
haven,t heard

I will call him tonight to see where he has been
 

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Bird's on Vacation. Maybe John is too.
 

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Discussion Starter · #5 ·
Bird's on Vacation. Maybe John is too.
Yea I was talking to both

what do you thin about the vac on my car. also the through out is making noise again but only when the it hot
but after all that has been done it really gets up and gos.
 

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Yea I was talking to both

what do you thin about the vac on my car. also the through out is making noise again but only when the it hot
but after all that has been done it really gets up and gos.
Run it till the wheels fall off. Then, rebuild it.:thumbsup:
 

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Your vacuum at idle can be as high as 20
At 2000 rpm that sounds high if anything, but it is different under different conditions. Is it in neutral, in gear? Readings at idle are just a starting point.

Tape your vacuum gauge on the windshield in front of you and drive on a level surface at a constant speed and take readings. This is where your advance works with vacuum. Then take readings at idle, in and out of gear and under different driving throttle positions.

All engines are different. The recommended 36° and 52° isn't written in stone. Big blocks as a rule run better a little less advanced.

If your only change is disconnecting the dist vacuum at idle, then I would say you have too much advance at idle.
Anything is possible, take the readings first.
 
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