If the oil has been in a long time drain and refill with 30W and 1 qt of auto trans fluid (has a high detergent). Run easy for 200-300 miles, drain and replace with 10W 40 for an engine that old in that climate. (I use Valvoline High Mileage) In the summer a quart of Lucas additive wouldn't hurt. Condensation and acids in old oil will eat bearings. The trans fluid will loosen deposits in an old dirty engine.
