[Diesel_Dave]

Yes, when you're concerned with temps, just keep an eye on the coolant temp. When starting up, the temp should continuously rise until the thermostat opens (typically 180-200 deg F), and then fluctualte slightly within a range of +/-10 deg F or so. If the temp starts to rise above that level that means you have too much grille blocke--because the engine can't stay cool enough with the stat full open. If that happens, start taking grille block off.