Are your plug wires getting too close to the exhaust? These cars in V8 form generally run in the 210-220 degree range right off the showroom floor with no ill effects to the plug wires...V6 cars in the same range or slightly less temp...the fan switch is designed to turn on at about 210-215 degrees, so it's not uncommon to see these cars run in this range. By the sounds of it the wires themselves are too close to the exhaust manifolds...if this is the case any plug wire will burn up on you...you may need to go to a different type/angle of spark plug boot to cure this problem..
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Shawn's Auto Repair and Performance, SW Wis.
www.shawnsautorepair.procarcarezone.com
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