Congrats on the nice time. I have been out to Lapeer 13 times int he past 3 years with my Camaro, making over 150 passes. The one thing I can count on at that track is the inconsistency of track prep. Sometimes we hook sometimes we don't. I would think that if you can catch the right day, (usually early spring or late fall), with good air, get those tires warmed up well, allowing that 60' to drop a little more. You should see another tenth or two while still in stock trim.
Have you heard of our club?
Detroit 5th Gen Camaro club.
http://www.detroit5thgen.com/members/home
Come check it out, join us, we have many members who go out to Lapeer and make a day of it. We do many of the local events together and hang out often at various locations. Would love to see another 1LE join up.