The 1991 350 cubic and Chevrolet engine spark plug gap is .027. Most spark plugs will come pre-gapped from the manufacturer.
.060
0.060
The Spark Plug Gap.035 (In thousandths of an inch)
The spark plug gap for a 1991 Chevy Silverado 2500 V8-350 is .035, according to major spark plug manufacturers (i.e. Autolite, Bosch, Denso, NGK).
On my 1992 350 van it's .35 gap
personally I would use an iriduim plug.
20 ft lbs
.045 inch.045 inch
According to the manufacturers specs on the emissions sticker it is .035.
all of the information I have found to date indicate it should be 0.35
If your asking about FREEZE OUT PLUGS then it has 8 of them.
The 1986 Chevrolet 350 cubic inch engine spark plug gap is .027. Most spark plugs will be pre-gapped by the spark plug manufacturer.