408 tuning with a Wideband sensor

Took the car for a ride after swapping the jets to 69 and the PV to 4.5. Getting mid 13s at cruize now. I noticed hesitation during light acceleration on the freeway so I backed the timing off 2 degrees. When I accelerate on the freeway the AFR goes lean to around 16 before richening back up. I'm thinking I need one of 2 things. Either larger pump nozzles or to enlarge the PVCRs. Any thoughts??