Retune my entire carb after installing new heads?

I finally installed my aluminum heads (low 290's cfm) to replace my hand-ported iron heads (doubt they made 250). Now my 451 runs a lot leaner everywhere, around 1 full point AFR. Cruise is more like 15.5:1 but no surging, so that's ok. The idle is now much too lean, showing around 16:1 after full warmup, and continues to spiral in (gradually lean out and slow down until it dies), especially when fully hot. Used to be more like 14:1 and my [email protected], .652" cam was happy with that.

So do I need to redo the entire carb tune now? At idle or cruise, aren't the throttle blades and the bypass air the primary restrictions to airflow, not the head (so the increased head flow at WOT should not affect it)? Vacuum seems about the same.