Spark plugs last a lot longer then they used to because the no lead gas does not have the erosion effect the lead had. We used to replace plugs on these old trucks about every 10,000 miles. You can't run them 100,000 like the modern car's though. About 25,000 would be about right. You can inspect 1 or2 at random occasonally & check for foriegn deposit buildup & erosion. If they are OK keep going.
Last edited by Wrenchbender Ret.; 12/30/2010 9:52 PM. Reason: Left out the T in can't
