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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!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
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| | | | Joined: Jun 2004 Posts: 8,597 Riding in the Passing Lane | | Riding in the Passing Lane Joined: Jun 2004 Posts: 8,597 | One is full manifold vacuum & the other is called ported vacuum. The ported vacumm has no vacuum at idle. Most of the time its best to use full vacuum for the vacuum advance, but sometimes the ported works better. If it surges & idles rough at idle the ported may work better. If its an auto trans. & it clunks or lurches when you put it in drive or reverse sometimes the ported will work better after setting the idle speed down. Its a matter of experimentation.
They say money can't buy happiness. It can buy old Chevy trucks though. Same thing. 1972 Chevy c10 Cheyenne SuperIn the Gallery Forum | | |
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