UDS Pork Loin - What Temp?

Bought a pork loin from Sam's this morning and soaked it all day in soy sauce and several minced cloves of garlic. It's been on for about an hour and half with the UDS at 300 F (trying to get it down to 250 F). The last few times I have cooked on the UDS, I left things on too long and dried things out - actually they were OK when I took them off the grill, but way too dry when reheated. The chart says 140 F to 150 F for medium - I am thinking 145 F. Any other recommendations when I should think about taking Mrs Piggy off?

Thanks,
Mark