Diesel #1 or #2 for 1650

I bought a 1650 diesel narrow front off of my uncle. He says to run #2 in it now. All the time I worked that tractor for him, late 70's and eighties he insisted I had to put #1 diesel in it and the 1755. Ford 4000 had to have #2 diesel. Gleaner, Oliver 66, stock truck, dump truck and pickups were all gas. When he bought a Gleaner with diesel engine and stock truck with a diesel he says he switched the 1650 and 1755 over to #2. The 1650 is hard to start now, am replacing battery cables they are bad. The engine also smokes all the time now, has not had a load on it for 4 years. I know it needs to drag a plow around for a while, just need some place to do it.
He had the 1650 engine rebuilt and never broke it in. He quit farming and then sold it to me 4 years later, I have not run it other than pushing snow and on the road.

Here in England there is red diesel, for field use and white diesel, for road use. the only thing diffrent with red diesel is the colour and cost (tax free).