Where are good 1,2 shift points in (mph) for a performa built lev2 and 408 with 3.89 gr? i plan to set limiter at 6800

 

That varies with the car and the converter. and ussually requires a bit of trial and error unless the tuner is very familiar with your car and power.
Its affected by everything from as i said the stall, The engine power , rear ratio.
And the setting must be ajusted in both MPH and RPM

 

A street tune or Dyno will help you nail it. If it is a new tranny there are a few other things that should be looked at too.....