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Apr 26th, 2026 | | AD Chevy Trucks  Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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| | | | Joined: May 2001 Posts: 7,438 Extreme Gabster | | Extreme Gabster Joined: May 2001 Posts: 7,438 | On my '54 GMC 248 I disconnected the tube to the vacuum advance from the carburetor and checked the reading there. The manifold port has a hose to the power brake booster. I left it connected.
The book says I should get a reading of 18-24. I get 9.
Which port should I be checking? Should the other port be capped? | | |
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