1967 GMC Pickup 3/4 Ton

Make:	GMC
Model:	Other
Year:	1967
Mileage:	97544
VIN:	PC5677B
Color:	Gold
Engine:	305 V6
Cylinders:	6
Fuel:	Gasoline
Transmission:	Manual
Drive type:	RWD
Interior color:	Black
Vehicle Title:	Clear
Item location:	Speculator, New York, United States

1967 GMC Other Additional Info:

Registered, inspected and insured. New Battery. New brakes, brake drums, brake cylinders, brake lines and master cylinder. New wheels and tires. Runs good. Some rust at bottom of doors. 305 cubic inch V-6. 4 speed transmission. Have new cab mounts. The pile of parts on the cart are all parts for the pickup body except side panels, inside fenders and tailgate. Put together a new pickup body or make it a flatbed. Garage stored all winter.
Here's the story. I bought this truck 2 years ago to teach my grandson mechanics. He will be in his Junior year at a tech high school in Connecticut this Fall for auto mechanics. He and I worked on this truck on and off for the last two summers. He is not interested in having the truck for his daily driver so we are selling it.
The engine had low compression on cylinder #6. We used a technique that I've used in the past where we removed the old oil and filter, replaced the filter and filled the crankcase with automatic transmission fluid. We then ran the truck at various RPM for 3 hours and removed the automatic transmission fluid, replaced the filter again and refilled with oil. The compression in all cylinders was up and the same. My thought is that it either had a sticky ring or valve. The ATF cleans the interior of the engine.