I am going to change them this weekend. What should I put in? Should I run one step colder?
What year 'stang do you have? If its a 99-03, be careful! There's a lovely little "defect" that Ford refuses to acknowledge that can result in spark plug/coil blowout. I became part of what is known as the "poptart" club yesterday due to this problem.
Search on "ford spark plug blowout" if your car is one of these models...
I wish they made silver plugs, and i'd run them!
Motorcraft AGSF-32C's at .054. Dont bother w/ special metals or special 4 arc arm designs.