Probably an easy question to others but what trans. do I have in my car? Look at sig.

 

You have the 4L60E, 4 speed automatic. They are an electronic version of the 700R4 transmission used in the 80's and early 90's, and a descendant of the old 3 speed TH350.

Unfortunately though, they don't have such a great track record. It seems a lot of 4L60E's fall victim to the torque produced by V8's................especially if you start doing engine mods and increasing engine HP and TQ.