408 tuning with a Wideband sensor

crackedback said
What vacuum does it pull on the highway?

You may need a higher number power valve so it opens earlier.

I'd put the timing back to where you had it and tune it there. If it's not pinging under load, run it there.

I'll try to get a vacuum reading while driving this weekend. I backed off the timing because i think it was pinging under load but that may have been caused by the lean condition.