Lack of power in 4th

[farmer]

To muddy the water even more I pulled out a vacuum gauge and attempted to diagnose the engine problems and set the timing via vacuum.

Truck warmed up, vacuum advance disconnected, timing right at 5 degrees I had around 11" hg, though it was fluttering. Loosened the distributor and advanced it til it read 16-17" hg and retarded to 15-16" hg, still fluttering. Snap the throttle it dives to 0, recovers to 20, and levels out back 15-16. Supposedly that means rings are shot. Checked the timing with a light, and without timing marks it looked to be at least 20-30 degrees, which seems absurd.

Finally test drove it like that, after hooking up the vacuum advance. Still struggling up a slight grade to maintain 30 mph. Ran about 5 mph faster downgrade. Could be too much advance with the VA hooked back up. I want to try the vacuum timing with the VA hooked up.

Talking to a friend of mine about what the vacuum gauge was telling me, he asked about the PCV. Mine isn't hooked up, just open. He told me to fix that and try again.

[Nailhead]

To muddy the water even more I pulled out a vacuum gauge and attempted to diagnose the engine problems and set the timing via vacuum.

Truck warmed up, vacuum advance disconnected, timing right at 5 degrees I had around 11" hg, though it was fluttering. Loosened the distributor and advanced it til it read 16-17" hg and retarded to 15-16" hg, still fluttering. Snap the throttle it dives to 0, recovers to 20, and levels out back 15-16. Supposedly that means rings are shot. Checked the timing with a light, and without timing marks it looked to be at least 20-30 degrees, which seems absurd.

Finally test drove it like that, after hooking up the vacuum advance. Still struggling up a slight grade to maintain 30 mph. Ran about 5 mph faster downgrade. Could be too much advance with the VA hooked back up. I want to try the vacuum timing with the VA hooked up.

Talking to a friend of mine about what the vacuum gauge was telling me, he asked about the PCV. Mine isn't hooked up, just open. He told me to fix that and try again.

Hang in there, you'll get it-- just keep your eyes open & don't disregard any clues, or make any assumptions. If I had kept this in mind, my truck wouldn't have spent last winter dead in my yard.