I have acquired a 270 GMC engine to replace the dead 228 in my '53 1/2 ton. The engine came from a salvage yard truck and appeared to have been spared exposure to the elements, the hood was intact and down, air cleaner still installed, etc. Removing the soft plugs revealed a water jacket with significant accumulation of rust and dirt...about three pounds and over a quart in volume. It is incredible to me that this amount of crud could accumulate in the water jacket but more to the point if the jacket side of the cylinder walls have corroded to the point of failure. The mechanical parts of the engine are at original specs for the journals, bearing clearances with no scoring on the journals and cylinder walls. The truck odometer read 84,000 miles but no way to know if it is actual. Has anyone had similar findings/experience or knowledge of the design thickness of the cylinder walls? I am leery of this because the 228 failed because three of the cylinders, 3,4 and 5, developed circumferential cracks on the left side, about an inch down from the top deck. All cracks were in the same position of the cylinder wall. We did have to bore the engine .040" over to clear a rust spot in one hole. Best guess for cause of the failure is from a sand core shift during casting.
