I got my 98 z-28 two weeks ago.78000. miles one owner.Its a automatic.It has flowmaster catback system on it and k&n air filter.Going to put a gms lid on it and katech motorsports ported tb.Was wondering what my car would run in the eighth now and after.I live in ky so conditions should be fare.thanks.

 

Not sure on 1/8th but I can give you a rough idea on 1/4 then the 1/8 can be calculated from that. I would guess 13.4 before 13.2 after, which is 8.4approx in the 1/8th.
Enjoy

 

This is just a guesstimate as my 01 when it was stock and just a lid ran 13.4.

 

Thanks!!!!!