We used a Toyota 4.7 V8 to replace an industrial engine in a mining operation that turns a ball mill. This is our second such application. If there is a severe classification for a motor vehicle I'd call this service brutal. This engine runs for 8-10 hours at a stretch, fully loaded at 4-5K rpm and we converted it to natural gas. This kind of load would kill an ordinary engine but this Toyota V8 is doing just fine. It has run the equivalent of 100K road miles so far pulling down a tremendous load. The clearance for the mechanical valve lifters is still in spec and it burns very little oil. We've added a larger sump (12 qts), an oil cooler and a larger coolant radiator with a big electric fan because this engine does not move. And we've added a great big paper element air cleaner and a larger than stock oil filter (Mobil 1, M1-209) and a bypass oil filter. For the cooling system we use distilled water and zinc chromate with a water soluble lubricant, a filter and a sacrificial disc. The oil is Red Line 10w-40 and we us no additives. We trust the oil to do it's job without us messing with it. The replacement industrial engine would have been $12K. So we went to the junk yard and got a Toyota pickup with the V8 engine that had about 10K miles before being totaled. You can do a lot with a welder, plasma cutter and some cutting and fitting.
This setup has now been copied by some of our friends in the same business and the results are very good. This is one very good engine.