1993GMCPU

Motor was rebuilt using recondition rods, ARP rod bolts, H345NP40 Pistons, 76 cc heads shaved .020 with .015 Fel Pro 1094 head gaskets, Edelbrock's 3704 TBI Manifold, Proform Distributor, MSD coil, Turbo City TBI around 590 CFM-Police style matched injectors all from Turbo City.

Plugs seem to run rich and right now, sent O2 sensor to Bosch and waiting to see if they will replace it and it was a bad new one. Any other things that I should check? All new gaskets and did block off exhaust crossover but left EGR hooked up.

Replaced most items when we changed from 4.3z to 5.7 motor, and with gasket and head changes up compression a little from 8.5. Around a -.046 change in combustion chamber which I hope helps live with 12-402-4 cam. Open chamber air cleaner with K/N filter, 3" pipe and cat to 3" Flow Master, 40, with dual 2.5" out. Considering real dual exhaust if room below truck which may help get exhaust out more. Cam well maybe I needed a dual pattern other then just on duration but on lift. ANY IDEAS welcomed, 3.42 rear gears.