Hello, I'm new to the forums and new to (or soon to be) Oliver tractors. I have six old tractors already, but have always wanted an Oliver with a Detroit Diesel. One has come up for sale, but I was hoping for a little enlightenment from those with more experience. It says (the decals) it's an 1855, but it has a 4-53 Detroit engine. No where can I find any mention of an 1855 with a factory Detroit. It could be a re-power, but if so, it is done awfully well. The serial number tag falls in as a 1971, the model number is 575-22280. I asked the seller, and he says that Oliver themselves offered a kit to re-power the tractor with a Detroit. I can't seem to find any mention of it. Has anyone ever heard of this?