[caverman]

I think you need to get off the OEM wheels as well. They are HEAVY pigs. Look good but weigh a ton. You should get you a set of Mickey Thompson on 18" wheels at minimum. If you can swing a whole set of front/rear Welds or something similar it will be even better.

Your 60' is no good at all. You must be blowing the tires off the line. Do you have a line lock? You might get one and really try heating up the tires.

What RPM are you leaving at? What are you shifting at?

There is definitely an issue going on. I have a stock motor with just headers/intake/tune at about 415 rwhp. With a set of 18" MT on back and OEM wheels on front I'm still getting consistent 8.1 1/8th mile @ 90 mph and that's only with 1.9 60' times. I think I can get into the 8.0 or 7.9 with more seat time and maybe changing my shift points and/or launching RPM.