We have all done it, overtightened a bolt and blown out the threads. When a bolt starts to tighten up and then go suddenly loose, you know that the threads are toast and now you have a problem.

When a bolt or screw breaks off it leaves the hot rodder feeling befuddled and without hope. But take heart—Summit Racing Equipment, Harbor Freight, and Dave Akard of Burbank Speed are here to help ...

Spark plugs that haven't been changed for a long time can become one with the cylinder head. Fortunately, it's possible to repair damaged threads instead of scrapping the head. (Photograph by Chris ...