1977 Ford E350 460cid vacuum diagram?

[GunsRBadMMMMKay]

But I finally found the VECI sticker and looked at the gap setting. .42 - .46 is what it said and I set them all to .35. Do you think that could be the problem right there? I should regap them any way just because it calls for it but its a true PITA to get to the front 2 on both sides.

I'd set them to spec, if your spark is to quick/short it can have trouble evenly igniting all the fuel in time for the cycle.

[Great-Kazoo]

As gunsRbad said, You're not creating enough spark @ 35 to ignite fuel / air mix. Not only are you not having proper ignition of fuel. Any unburnt fuel not fouling up the plugs, exhaust valves, is mixing with the oil. Incorrect gap can and will cause a series of other issues if not taken care of.

[ben4372]

A few thou off the spark gap is not a issue. But it does beg the question of weather the ignition is up to the task. Get a spark checker. A timing light is your friend too. you may have a worn timing chain causing erratic timing, That was built in the age of nylon timing gears.

[Great-Kazoo]

A few thou off the spark gap is not a issue. But it does beg the question of weather the ignition is up to the task. Get a spark checker. A timing light is your friend too. you may have a worn timing chain causing erratic timing, That was built in the age of nylon timing gears.

.10 difference will cause an issue. Consider the normal plug gap now shortened .10 unless he's inspected them since the initial install, i would say there's potential some of the ground electrodes have been pitted / compromised. If it was a tune up - emissions test, probably not. A Full tune up should include checking the timing. BUT some folks skip or overlook it. It's electronic ignition what could go wrong .

Timing chain is easy to check.