Low engine temps

Depending on what your weather is, when I was driving these cars year round I'd have to block 1/2 the radiator off with cardboard to get it to operating temp when it got really cold. Yesterday morning was -10° at my house, today was a balmy 5°. If your temps are cold, you may need to limit the airflow thru the radiator to get it hotter. Think like the heavy trucks with the grille covers...