Always been a big block ford or chev due to farm operations. Did the job, but fuel to expensive. Now all tractors but one diesel, and just purchased a 98 3500 4x4 auto 12v 117K and scared to death of it. After purchased contacted old owner he said put $5500 in front end, $5800 in eliminating a algae problem encluding pump, enjectors, fuel lines and cleaning out both tanks spare tank 70 gal. on top. He said after all this work blew engine #6 cyl pulling 5th wheel up grape vine in California. (Did'nt have pyrometer) and dealer wanted $10K to fix. Sold truck as is to Diesel shop. Point. I bought truck not knowing history. I can't see work done on front end other than tie rod end, fuel system looks like nothing was done other than hole in bottom of tank on top patched over (and leaks) Now the clincher he said the engine had to be repaired or it would'nt run. I've repaired and replaced many engines in the last 50 years. This one looking underneath has'nt had the pan dropped, motor mounts look like they have been stationary since 1998. Basically it looks like he got took, and someone fixed a turbo or whatever and put it back on the road. Is their some way I can use the engine ID number to see if it is the orginal engine, or is their something else I'm overlooking regarding maybe it's a replacement engine. Help