The 1155e came from the factory with the cummins 12 valve 5.9, the 1150e dozer models came with the cummins 8.3 rated at the exact same hp as the loader models with the 5.9. There is a turbo on the 5.9, the 8.3 is naturally aspirated with no turbo on them, I own both e model machines, have for over 20 years now. I've never seen an E model machine of any age that came with a case engine in them, not saying a really early year version might not have one Tennaco was trying to use up before switching to cummins, not sure what other countries had in that model either, maybe case stuck something else in and shipped them overseas somewhere.
As for your crank in the 504, if you want to spend money on that engine, I'd start by asking your local machine shop what they can get for parts, [don't think case offers much anymore for parts on the 504] I'm sure they'll want to see your crank first to know if they can or can't grind it to spec. If it were mine, I'd take them all the parts, have them looked over, heads, block, crank, cam, rockers, oil pump and all the rest to assess if its worth fixing at all. There's no sense in taking in the crank, either grinding it or finding a good one, if your heads are junk and the cam's shot and those parts aren't available either. I'm sure a pump shop can look over the injection pump and injectors as well and give an idea of cost to fix them and check them over. I'd have all the estimates in hand before I gave much of any go ahead to actually go through them. You can also check with some engine rebuilders, to see if by chance they have a complete rebuild sitting on their shelves to find out what that cost is, also if they'd be willing to buy your core and if so what its worth, or maybe trade your core in on a rebuilt 8.3 or 5.9 which would be ideal in my opinion.