I’ve come into possession of a Case D-850 with a broken crank. By all of the research I’ve done, it appears both the 301 and 336 have become both difficult to source parts for and reconditioned motors seem almost non existent. Looking down the path of replacing the motor with a Cummins 4BT. Wondering if there’s anyone around has successfully undertaken the task. Located in Australia.
I don't remember who it was, but, one maybe two members here on HEF have done the conversion. Crankshafts for Case 301 and 336's are readily available in the US. The only problem is that you would need to buy a complete engine to get one. That could be a good thing if you consider all the other parts you would have. Case put both engines in thousands of agricultural tractors. which means you need to search farm equipment salvage yards. https://www.vanderhaags.com/detailview.php?manufacturer=case&model=a336bd&inventorytype=engine-assembly&wcf=parentmodel