Has anyone done it?

What was the cost?

How much HP gain?

Anyone considering using the 317 cast 6.0L heads?

I use Stage II 6.0L heads on my car. I had them milled .030 so I would not loose compression due to the bigger chambers on the 6.0L heads.
I would go with a set of stage II 6.0L heads milled .030 a TR 224/224 cam, LS1 Edit, and a good exhaust. I should run you about $3000-3500.