First off, dump the 20W50 and put 10W30 in your engine. You could end up pushing the bearings out of your turbo with that heavy of an oil. Simply looking at the info you've provided and equating it to sea level where I race, your chip is too rich in the bottom end[particularily at 46psi baseline fp] and too lean at the top. 46lbs fp is lots and lots if your at sea level approx and your 60' says with that high a fp you're dogging it at the line, possibly due to overfueling. There's nothing wrong at all with 765 at the top of 3rd with 20lbs of boost, but as mentioned above an O2 reading is about as trustworthy as a hooker on a Greek Freighter. Get an EGT and be done with O2's.
HTH
Jim