This is getting interesting....There is no hole in the manifold for a vac port.....To shed some clarity on this truck...I recently purchased it (1967 K20 - 250 cu in) When I showed up to look at it, I could tell it was already up to temperature and the air cleaner was on the ground....the seller mentioned it had a carburetor issue....putting that aside, I focused more on the remainder of the truck....Once the deal was made the seller suggested flat bedding to my house about 25 miles away....I convenience him to deliver it by driving, which he did....I followed and the truck appeared to run well...I saw no smoke coming from the tail pipe.....As to date, I never drove the truck, other than in his driveway to check the clutch, brakes & 4x4 operation...
