289 ford v8 rebuild?
If it is white smoke, it is antifreeze or coolant entering the engine and trying to burn with the fuel. Check to see if the proper amount of antifreeze is inside the radiator and the overflow bottle. Also check to see if antifreeze has contaminated the engine oil. You can look at the engine oil dipstick, or look at the under side of the engine oil filler cap. If the oil is contaminated with antifreeze, it will have the appearance of a chocolate milkshake (milky white and maybe foamy). Do not start the engine if the oil is contaminated with antifreeze, as serious internal engine damage can result.
How did antifreeze get in the oil or cylinder in the first place? The engine probably overheated and a head gasket failed due to excessive heat, thus allowing antifreeze to enter the cylinder. If this is the case, check your theromostat and replace the head gasket carefully.