I have a motor (not running yet) installed in a chassis and despite trying to blow it out a bunch w/compressor and pressure washer, the coolant coming out of the block still displeases me greatly (rusty water). I have considered buying enough vinegar to pour in through the open block (have the thermo housing off and have back water drain out) and let sit, but then considered muriatic acid/water (have been reading searches on here)....but then I thought, should I just wait until engine is running, will the engine heat help alot more in this quest to remove rusty water (old farm truck had the 235, surely been ran on well water). It pumped out lime or calcium first then moved to rust. Back plug is unstopped (took awhile w/flatheads), and water coming completely through. Your notions?
