Spark plugs keep getting loose?
I am the tech manager at Autolite spark plugs. What part number are you installing and do you have stock heads? The stock head has a tapered seat that is a slightly different angle than the plug taper seat. This causes them to lock together very tight. I have seen many guys use an aftermarket head and have this problem when they continue to use the stock plug. Most all aftermarket heads use a gasket seat plug. We have an extensive lookup of recommended plugs on our website for nearly every aftermarket head there is.
autolite.com, open the parts lookup and open the box in the lower left hand corner.



