You will hate yourself if you buy the 2947. There is almost no room to get the water pump bolts in. I had to locktite studs in the water pump and use nuts to hold the fan clutch on. Very difficult.
You shouldn’t need the 2947 if you run the 69 and back cast water pump. It is about 3/4 inch shorter than the 70 and up aluminum one.
Many aftermarket radiators are thicker than stock and are positioned closer to the engine. Do you homework Before you buy.