whats the 1/4 mile time for a 2002 ws6 trans am stock?

Should do low-mid 13s. Hard to say, times will vary significantly with different options/driver skill.

i'd say more like 13.5-13.8 with your typical driver. For example my cousin ran 13.1@109 with a full bolt on 02 firehawk with 2.1-2.2 60ft times. With your VR4 you will rape them off the line.