On Sep 20, 1:52*pm, "Steve Barker DLT"
wrote:
You'll want to Tee in an air admittance valve after your trap under the
sink. *That'll keep the 8' run of 1-1/4 from sucking your trap dry.

That's what I was worried about. It'll definitely be (dry) vented but
as Wayne has suggested,
I'll likely go with 1.5" Cu scraps that were destined for recycling.

Thanks again everybody.