408 tuning with a Wideband sensor

Can't help with the holley, but i have a similar combo, with a 236/242 @0.050, .544 lift, 5 speed, using a large boare TQ. I idle at 850, and cruise at 14.5-15.5 depending on temperature. 18 initial, 34 all in on the timing. WOT is around 12.5. Just keep tinkering. The Wideband A/F was the single best thing I did for tunability. That and a strip kit with jets/metering rods and I can tune it to any AF I want.