My best run with all the mods listed below was

12.67 1/4 mile @ 106.9 mph
1.779 60 ft

It seems that everyone else running similar setups are running between 110-120 mph and better times. I have about 100K miles on the stock 4L60E tranny and it is bouncing off the rev limiter when it shifts from 1st to 2nd. Also I noticed the o2 sensor were reading around 850's - 940's. Could the low times be due to the transmission slipping or am I possible running too rich?

I have reajusted the lifter to zero preload to see if I gain anything (Will know tomorrow)

 

Your mph is way off, most likely due to the tranny slipping.

 

12.6 is not a bad time for that cam, but you should be trapping a little higher. i would also point the finger at the trans.

edit: just noticed you have heads. nevermind, you should be about a flat 12 IMO.

 

I'd expect a much higher trap, something is definetly wrong. The tranny slipping definetly doesn't help but you should still be much higher (I'd expect at least 115 at sea level). Those bolt-on times you're running.

What are you doing for a tune? You have a dynotune for all those mods I hope? A tune will make or break you.

What springs? What's the lash on the rockers?