Also forgot to mention, if the dozer has a reversible fan on the case engine and you want to keep that on the cummins engine, you need to know the distance from the fan to the radiator, this is important because as you turn the fan blades around, the blade itself actually gets closer to the radiator, that measurement is critical to know because if you don't have the measurement from the transmission to the torque converter exact from when the old case engine was installed and keep it the same when the cummins in installed, you can't turn the fan blades around once the radiator is installed due to not having enough room in the engine compartment. My dozer had a reversible fan on it, they all do and I use and love them and refused to give it up, so to make a long story short, the distance from the fan blades to the radiator was reduced to the bare minimum in order to keep the reversible fan on the cummins engine and still get everything to fit under the hood.
If you look at and measure a D model 850, the measurements won't be the same as a C model, most all D's were long track, meaning they had one more bottom roller under them making the engine compartment slightly longer to make everything fit better and have more room to work with.
Not sure what truck this engine came out of, but you'll more than likely need to turn the oil pan around in order to get it to fit over the cross member of the dozer frame, then you'll also need to buy a different oil pickup tube as well and just turn the pan itself around.
If it has a deep oil pan from a truck, you'll also need to torch out some of the belly pan gussets on one section of belly pan to get them to fit back up on and the oil drain hole will no longer line up with the one in the belly pans. The dip stick tube needs to be shortened as well and cut off the dip stick and etch a new oil level mark on the shortened dip stick, that and you'll need to move the dipstick tube to a different hole to fit into the oil pan once you flip the pan around, then replug the old tube hole. Once done I cut a square hole in the lower side panel and made it into a hinged door to get at the dip stick to check the oil, the reason the longer tube won't work is the truck version has a wider arch and it won't fit under the hood once the engine is in, a short cut off version then fits under the injection pump and is out of the way of everything, but you need the hole in the lower side panel to use it and be able to pull the dipstick out. Later versions that came from the factory with the 5.9 in, had a longer tube mounted through and around the injection pump and you pulled them from a cover in the top of the hood or the H model had a whole side panel flip up to access the dipstick.
Most any injection pump guy can change over the governor on the injection pump to make it work instead of truck governor to a machine governor and also ask that person how to adjust the governor for idling once its in the dozer in order to get it to idle down fast so you can shift the dozer, they work fine, just takes some adjusting to get it to work right.
If I recall the exhaust manifold we just flipped over so the exhaust sticks up instead of down but won't line up with the pipe going out of the hood. I just made an adapter that slipped over the exhaust manifold that had an offset in it that lined up the exhaust to the old pipe in the hood, was simpler than dinking around with the hood to get it to line up, also if you ruin or damage the hood, any hood off any older case 850 will then work and just bolt right on. I also don't have a muffler on mine, its just a straight piped up and out of the engine compartment. The D and later models have a muffler that attaches to the manifold and a larger hole is cut into the hood to accommodate it, newer versions still have a small muffler under the hood, on a C model you won't have the room to make this work unless you cut a hole in the hood and mount it directly onto the manifold like the D model or flex pipe it out and mount the muffler along the limb risers or something like that. I wear hearing protection anyhow, so I didn't take the time to worry about a muffler and still don't have one, the six cylinder cummins sounds really nice under a load the way it is.
You'll need your injection pump guy reset the pump and injectors down to have 90-100 hp, much more and you'll tear the torque and transmission up, think mine is in that 100 hp mark and runs really nice.
You'll lose your tachometer when you do the swap, the case was a mechanical drive and if you want, you can get the electric drive off the alternator and switch the gauge in the dash, but it didn't matter to me. You'll need an adapter to switch the hose ends from the case pressure switch which is standard pipe thread to either metric off the cummins or vise versa, I just had a hose made up to fit the pressure switch on one end and a metric to fit the engine oil galley on the other end, so the hour meter and gauges will work right.
The wiring is pretty simple as well, just make up a new harness to go from the alternator to the dash through the pressure switch, we just mounted the circuit breakers which will be on the right side of the old engine, and bolted them up near the dash when we put the cummins in. I'd have to look again how it was done but if you get an alternator that is self exciting, like most trucks have, it eliminates a lot of wiring and headaches. If I recall, I just took the alternator that came with the cummins in and my fix it guy switched it over to self exciting and put new bearings and went through it for me.
If the truck had air brakes and an air pump on it, we just took the pump off and bolted a plate over the hole with a gasket, looks factory installed when it was done. For future reference, that cam drive for the air compressor on the cummins, is much cheaper to put a new hydraulic pump on rather than use the old hydraulic pump off the torque converter, also a whole lot easier to work on and get to verses the one on the torque converter or if you need it for a winch drive or something along those lines in the future.
Best of luck, it sounds a whole lot more detailed than it really is, the main things to bear in mind are the measurements you'll need before you begin. My issues came when we were part way done and the sheets of paper those measurements were on, got lost and nobody could remember them exactly, so we put the old case engine back in to get them the second time and then wrote them in marker on one of the side panels, but those were painted over once the engine was done and working.
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