As a relative newbie, need some advice. Converted '98 350 Vortec to TBI using 454 throttle body, 4 barrel intake and adapter. Have several injectors from 305, 350 and 454 TBIs. Purchased Cop Car injectors that are NOT marked supposedly 65 pph. Keep running into the same situation wherein the engine runs pig rich at idle. Fuel pressure at present is 14 psi. Just switched to 350 injectors and still runs pig rich. Installed adjustable pressure regulator and have it at lowest pressure setting. Still runs rich.

Found that Oring sizes and fit are critical in the fuel portion of the TBI. Got the wrong size, wrong fit and it hydraulically LOCKED the engine. Pulled all the spark plugs and rotated with starter. Got a gasoline bath. Tried to dry out plugs and reinstalled. Still misfiring and running pig rich. Went to the auto parts store for new spark plugs. Need to get these installed and try again.

Advise needed for this situation.