[stage1]

Took the car out for a drive with a new chip from modern muscle.Did a wot blast,check the scanmaster and it read 816 millivolts with 0.03 knock.My fuel pressure is at 43lbs line off.Should I turn the pressure down to lean it out a bit to get the millivolts down to the .77 to.80 range or leave well enough alone.I have a street chip set with 100 octane (sunoco). dunno

 

[The Radius Kid]

I'd leave it alone,but you could take it down 1/4 turn at a time and see how it does.
Watch your idle as well when you do this.
You'll find the sweet spot.

 

[Steve Wood]

go here, http://www.vortexbuicks-etc.com/tuning.htm and look at the O2 section-look at the graph.

You are wasting your time trying to tune by o2 voltage. Tune by what runs the fastest, not some meaningless number.

I would not be surprised to see that an .830-.840 actually ran faster than a .770.