UPDATE:
7-6-5 works like a charm! It was actually closer to 7-6.5-6 and then 5 min. or so resting. It was super-moist, and cooked completely through (my father-in-law likes well done and I'm a medium-rare guy so I think it was a happy medium).
I used a Chile-Lime rub from
Stubb's. Amazing flavor (as with all Stubb's products).